If someone is ignoring your boundaries, consider it a big red flag. "Some examples include standing too close to you (and following if you step further away), refusing to take no for an answer, or even 'innocent' activities like tickling you when you’ve asked [them] to stop," Amica Graber, a relationship expert for the background checking site TruthFinder, tells Bustle.

While some folks just don't know how to take a hint, dangerous people might do these things as a way of testing you, Graber says, in order to see if it's possible to go further.

When it comes to manipulative people — see: sociopaths, narcissists, etc. — many have a habit of staring intensely at others. If you happen to make eye contact, they won't immediately look away. Instead, they'll maintain that intense eye contact.

"They look at their target with [a] focused, intense gaze," usually as a way to test boundaries, Patti Wood, MA, a body language expert, tells Bustle. "They may do or say something uncomfortable right before or after the hypnotic gaze to test how the target responds."

To figure out if the situation really is unsafe, Wood says, try breaking eye contact or moving away in order to see how they react. If they get upset, or you feel a huge amount of relief, your intuition was likely correct.

While some people just like to talk, manipulators will try to dominate entire conversations. "This 'over talking' involves auditory space invasion and other paralanguage factors that show they are in control," Wood says. "They are often quite charming and good storytellers, so it may be hypnotic to listen to them." Chances are, they'll keep doing it if you keep giving them attention.

It's why being an attention-seeker who loves to talk and dominate conversations is another sign of an untrustworthy person. According to Shannon Gunnip, LMHC, BC-TMH, a licensed mental health counselor, these types of people can never have enough of your time or attention. "They may say or do things in a dramatic or over-the-top way to shock you or keep your interest," she says. "The more attention you give, the more they will persist. This type of person may not be trustworthy because they will take from you emotionally without giving positive energy back."

Since narcissists tend to get really upset when things don't go their way, keep your eye out for shocking mood swings when interacting with others. As Wood says, "They can shift all their nonverbal behaviors in the blink of an eye and transform themselves."

This might include switching from really sweet to super irritated, and then back again. Or they might morph into an entirely different "character" in order to get their way, Wood says. It can be so manipulative that you might not even realize it's happening until the person's already sucked you in. So take note of how someone acts when they don't get their way. If you see them transform into a totally different person, you may want to stay away.

While intense eye contact can be a red flag, the same is true for eye contact that seems oddly disconnected. And this is doubly true if you'd describe the person as being "dead behind the eyes," Wood says, as this is a trait common among narcissists and sociopaths.

Not everyone is great at making eye contact, but if you're getting other bad vibes, add this one to the list of reasons it may be safest to cut the convo off and get away.

If you only just met someone and they're already revealing all the skeletons in their closet, there's a chance they're not trustworthy or stable, psychotherapist Dr. Laura Dabney, M.D., tells Bustle. Not only does it show a lack of boundaries, but it can easily get out of control.

Basically, if someone is willing to pile all that on you within the first few minutes of meeting, it may mean they don't have total control over themselves or their actions. It's one thing to be trusting of others. But if this person sees you as someone they can vent all of their problems to, it can get emotionally draining very quickly. So at the very least, consider it a red flag.

If someone is being rude, you likely won't want to spend much time around them. And that's a good call, seeing as it's often a sign of deeper problems.

"Potentially dangerous people will often turn to belittling others in order to manipulate them," Adamaris Mendoza, LPC, MA, a licensed psychotherapist and relationship coach, tells Bustle. So if this person is making you, or those around you, feel uncomfortable, take note.

"How they do it can take different forms, but their intention is to make the other person (their intended victim) feel unworthy," Mendoza says. "They can turn to ridiculing how you look, your body, your goals, your friends, your work, and/or your dreams."

Again, since it's so manipulative, it can be difficult to spot. But by keeping an eye out for the signs, and knowing some of the tricks untrustworthy people pull, you can be safer.

If you show up on a date, and the other person already knows where you work, where you went to school, etc., don't take it lightly — even if they try to act like it's "normal to look people up."

Sure, it's common to do a quick search before spending the evening with a stranger. "But if someone starts telling you about information that likely showed up on, say, page five of your [search] results," Issa says, "this could be a sign that [it] went beyond the norm and crossed over into stalking."

If what they're saying is making you uncomfortable, don't be afraid to reach out to authorities. You can also go up to a bartender or server, if you're out to dinner, and ask them for help.

If your relationship with someone new seems to be developing at warp speed, it's easy to take it as a compliment. But, as Issa says, "oftentimes, people who are likely to harm others will sweep in quickly and forcefully and try to foster a sense of false trust." If it all seems too fast, or too good to be true, you may want to take a step back.

This may be someone who is big on risk-taking, and loves the new and exciting. "They tend to be impulsive," Gunnip says. "A risk-taker may not be a trustworthy person because they may bring you into situations that push your boundaries." There's a chance that this type of relationship could lead to something emotionally intense and unstable.

You'll also want to listen to your gut if someone is telling you to calm down, claiming a situation isn't scary, or that everything's OK — even when it doesn't feel OK, Issa says. This person may be trying to manipulate you into feeling a certain way. Invalidating your feelings could be used as a tactic to try to control you.

And the same is true if they are telling you what to think, as that is a way of disrespecting your boundaries. If that happens, you'll want to cut off communication, and move to a safer space ASAP. It's important to always remember that you're allowed to think and feel for yourself. If your gut is telling you that being around this person is unsafe, listen to it.

If it feels like they are trying to increase the intensity of your relationship faster than you are comfortable with, Theresa Leskowat, MS, LCMHC, a mental health therapist, tells Bustle, don't brush it off. They may not have the best intentions for you.

This might include not listening when you say "no," or pressuring you to change a "no" into a "yes." They may even give you ultimatums or act out if you don't respond in the way that they want. If you feel uncomfortable around them as a result, no matter the situation, give yourself permission to believe it's as bad as it seems — and then make moves to leave.

While it can be tough to own up to a mistake, narcissists will flat-out deny their involvement in a problem, often to a "creepy" degree. These are the types of people who don’t like being seen as the “bad guy.” They think they’re the only ones who are right, and everyone else is wrong. Because they think this way about themselves, they don’t feel the need to say sorry or admit any fault. In their mind, they did nothing wrong.

"When you do something bad, it’s normal to feel guilt. But a person that is less empathic and less trustworthy will be likely to avoid accepting any type of responsibility in order to avoid experiencing guilt," Dr. Clinton Moore, a clinical psychologist and founder of Cadence Psychology, tells Bustle. "This will often come across as ... not admitting to mistakes or refusing to [apologize] for anything."

If someone is dangerous to be around, one key giveaway is that they won't be able to control their emotions. And it likely won't be long before you notice a pattern in how they interact with others.

For example, if you're on a date and they start yelling at the server, that's a sure sign they aren't worth your time — for multiple reasons. Same goes for telling stories about how they "blow up" all the time at work, or seek revenge for small misunderstandings.

Moore says this behavior means they aren't able to "self-soothe," or calm their emotions in a healthier way, which is incredibly toxic.

There's a term called "splitting" used to describe folks who tend to have black-and-white thinking, and it often runs deeper than a habit. "The issue for these people is an inability to hold opposing thoughts and feelings," Moore says, usually due to an underlying mental health concern.

To them, you're either "all good" or "all bad" and never in between, Moore says. If you're dating this person, they won't be able to care about you while they're upset — they love you then hate you, hate you then love you — and it can become a problem.

It's something they certainly work on, but it's a red flag all the same.

A toxic person will create arguments wherever they go. "This can sometimes take the form of actions like pitting people against one another through manipulation and gossip," Moore says.

They might purposefully spill a juicy secret, for example, knowing the ensuing argument will somehow benefit them. And that's not the type of energy you want to be around.

A toxic partner is unpredictable. Are they going to text you 1,000 times or go silent for a week? Experts say not to take their erratic behavior lightly.

"Behaviors that are either aggressive or erratic are signs that someone hasn't get figured out who they are," Leah Rockwell, LPC, NCC, a counselor and owner of Rockwell Wellness Counseling, tells Bustle. When that's the case, she asks, "how can they then be good to you in a friendship or relationship?"

It may be advisable to give them space while they do that work.

Ever get the feeling you're talking to someone who's cold at heart? "Sociopaths and psychopaths are defined by their lack of empathy," Graber says, and may laugh at others' misfortune and suffering, or give off the vibe that they just don't care.

If being around someone like this makes you feel uncomfortable, it's OK to excuse yourself and leave. After all, how can you fully trust someone who doesn't seem to care about the feelings of others? "They may not be a fully fledged psychopath," she says, "but a lack of empathy is a huge red flag."

When untrustworthy people divulge information, it might feel like you're never getting the full story because details change as they speak.

"When you find yourself noticing that timelines, stories, or other pieces of information seem to be missing a piece, or don't match up with what makes sense, it's a definite red flag that someone may be untrustworthy or manipulative," Jennifer Silvershein Teplin, LCSW, a licensed clinical social worker and founder of Manhattan Wellness, tells Bustle.

Relationships shouldn't inherently feel very confusing, especially with communication. "I find that when clients share that someone seems to always leave something out or is constantly in shockingly strange situations, it means they're being manipulated."

People sometimes drop the ball, and that's OK. But if they don't seem to stay true to their word, Deedee Cummings, M.Ed., LPCC, J.D., a licensed professional clinical counselor, tells Bustle they're most likely untrustworthy.

However, your alarm bells should go off if they try to convince you that you're "making a big deal out of nothing" when you get upset or ask what happened, Cummings says. Making you feel silly or saying you're "confused" may be an attempt at manipulation and gaslighting.

As with apologizing, it's common for people to feel uncomfortable when hearing any type of feedback. But for those who are unsafe to be around, they may react to it by lashing out.

"People with more narcissistic traits tend to derive their sense of worth from positive feedback from the people and situations around them," Moore says, which is why even constructive criticism will be experienced as an attack.

"This type of response means you won’t ever be able to be your authentic self with this type of person," she says, "as you can never quite trust how they will react."