"If you ask someone how their day was, and you get a single syllable answer — it's often a sign that something's wrong," Amica Graber, relationship expert for the background checking site TruthFinder, tells Bustle. And this is especially true if your partner used to be chatty, but now seems closed off.

"Good or bad, we usually want to tell our loved ones about our day," Graber says. "Granted, everyone has off days so don't take it personally unless you get the same answer every time. If your partner is never up for discussing what they've been doing or how their day/week has been, they may be sharing it with someone else."

Similarly, it may be a red flag if your partner no longer asks about your day, or takes any interest in what you've got going on.

"If they no longer jump into the discussion, if they simply 'don’t care,' they may be looking elsewhere for emotional fulfillment," Joshua Klapow, PhD, clinical psychologist and host of The Kurre and Klapow Show, tells Bustle. "Disengagement is an emotional cheating red flag."

"If your partner is getting [their] emotional needs met elsewhere, that could even involve venting about the problems in your relationship," Bennett says. So if your partner used to be invested in fixing problems as they happen, but now seem a little too cool, this may explain why.

Unfortunately, it could also be a sign they're checking out of the relationship, possibly because they're becoming more invested in someone else, Bennett says. The only way to know for sure — and to work on fixing the situation — is to talk about it, whether they want to or not.

While not every conversation with your partner will be riveting and intellectually stimulating, it may be a red flag if they're suddenly all surface-level.

"If your partner is getting their emotional needs met somewhere else, they may not want to talk about their emotional world and stick to superficial topics," clinical psychologist Dr. Helen Odessky tells Bustle. "If you don't hear your partner talk about how things are affecting them, they may be getting their emotional needs met elsewhere."

"If your partner is secretive about a major area of their life — their family, work, or a hobby they are passionate about — they are probably getting their emotional needs met somewhere else," Dr. Odessky says.

If they aren't excited to tell you about these things, it may mean they've already discussed it with somebody else, and don't want to share it all over again. Or, it might mean they're hiding something. You know your partner best, so if something seems off, ask them about it.

You should be one of the first people your partner turns to when they have big news, not only because it will affect you, but because they're excited to share.

That's why, as Dr. Klapow says, "if your partner is making personal changes and not sharing them with you, they may be thinking about sharing them with someone else."

At that point, it may be time to rethink the relationship. If you aren't a priority, and aren't feeling like a "partner" in this partnership, you may even decide to move on.

One of the biggest red flags that a relationship is going of course, is if one or both partners stops talking about the future. If your partner used to talk about moving in together or getting married, and now can't even chat about it, take note.

As Graber says, "Someone who is investing their emotions elsewhere will be reluctant to discuss the future. If they're not 100 percent sure that they see you in their future, they'll want to avoid the topic at all costs."

While everyone is unique, in terms of how they show their affection, it may be a red flag if your partner suddenly stops talking about intimate things around you, such as how they feel or what they want.

"Maybe your partner used to say 'I love you' but recently stopped saying it, or physical contact has stopped altogether," Graber says. "Intimacy can also be sharing your feelings. Either way, if this has stopped, it's a major sign that something's up."

If you ask your partner how their night was and they're unable or unwilling to tell you, it might feel a bit upsetting. And rightfully so.

"If your partner seems reluctant to discuss last night's festivities with you, it's very suspicious," Graber says. "If they don't want to share any details as to who was there, where they went, or what they did, it's a red flag that something shady went on."

Of course, it's not necessary for them to provide a play-by-play of their social life. But in a trusting, loving relationship, couples usually want to share a few details with each other — especially when asked — which is why this may seem so strange.

Being in a healthy relationship means trusting each other, while also giving each other plenty of privacy. So it's already a red flag if you're worried about who your partner is texting. But even more so if they aren't willing to talk about it, should you happen to ask.

"They might be evasive and avoid questions about where they are going or who they are texting," clinical psychologist Robyne Howard PsyD, tells Bustle. "They will minimize your concerns and possibly blame you for asking."

It's fine if your partner isn't a big talker, or if they struggle to open up about their emotions. But you should never get the feeling that they're talking to someone else, instead of you.

If something's going on behind your back, they may seem "more irritable and easy to anger," Dr. Howard says, especially if you ask what's wrong or try to get them to open up.

It's OK if you aren't fulfilling all of your partner's emotional needs, or if they're not fulfilling all of yours. That's what friends, family, and therapists are for. But if it seems like your partner is checking out of the relationship — or turning to someone else in an unhealthy, emotionally cheating kind of way — pointing it out and talking about it may be a healthy first step in getting things back on track.