Perhaps the most obvious sign? “If your partner is not reaching orgasm after doing so easily in the past, it is possible that something has shifted,” Lawrenz says. There are lots of reasons why people don’t orgasm, from health concerns to mental blocks. But it could also be a sign they’re just feeling a bit bored.

You won’t know — or be able to make any positive changes as a couple — until you ask. “Having candid, kind, curious conversations in a place where the sexual contact is not happening can facilitate a safe dialogue,” Lawrenz says.

Does your partner constantly have plans? “When sex stops being fun, people get infinitely creative finding excuses to avoid it,” Anya Laeta, a somatic sex and relationship coach, tells Bustle. So take note if your S.O. is always busy with random tasks, especially if it happens right when you’d normally be having sex. Are they suddenly answering emails, walking the dog, or texting hours later to say they fell asleep? If so, this may be what’s going on.

"While some people are more active or passive during [sex], total passivity is a sign that the sex isn’t that enjoyable for your partner," certified counselor Jonathan Bennett tells Bustle. "Good sex involves passion from both sides, which includes touching and active participation."

If they aren’t switching positions, telling you what they want, or — even worse — staring off into space, you’ll definitely want to have a chat. Talking about sex with your partner will help you both get to the bottom of why they seem checked out so that you can work on improving the situation together.

Similarly, if your partner seems distracted it might mean they’re disconnected from their body, Laeta says. As a result, they’re unable to enjoy themselves — in which case, consider if your S.O. stops having sex halfway through to tell you a story or ask you a question. It’ll seem pretty jarring.

It’s also quite possible your partner uses these brief interludes to take a break because they’re experiencing pain during sex but they aren’t sure how to let you know. If that’s what’s happening, you should stop having sex and ask them how they’re feeling or if there’s anything you can do differently. This is a very real issue that may require a doctor’s input, too.

If it's typical for you and your partner to go to bed at different times, then you shouldn’t consider this a cryptic sign. But if they've just started slinking off to bed without saying goodnight, something might be up. "Nighttime is, after all, often the prime time for sex," therapist Kimberly Hershenson, LMSW tells Bustle.

If it becomes a pattern, don't hesitate to ask if something’s wrong. From there, you could even ask if there's anything new or different they'd like to try in bed, which will obviously be exciting for the both of you. Sometimes it's just about opening up a convo about fantasies and/or new positions, and before you know it, you’re having great sex again.

Take a second to think about the last time your partner initiated sex. Have you been the one putting in all the effort lately? If this change seems unusual for your relationship, it might be a sign your sex drives aren't syncing up. Or that your partner isn't enjoying sex.

"Most people have a way they initiate sex and it doesn't take long before you know how your partner initiates and vice versa," professional matchmaker April Davis tells Bustle. It’s why you might notice that, instead of cuddling with you on the couch — which has always led to sex in the past — they suddenly want to sit somewhere else.

While it's obviously nice to give each other undivided attention during sex, it may be a sign your partner isn't enjoying themselves if they don't want you to return the favor.

"They may say things like, 'I don't need to climax' or 'I'm not in the mood right now but I'll take care of you," Julienne B. Derichs, LCPC, a licensed professional counselor, tells Bustle. "You don't get a hard 'no' but sex is no longer something you both share, and this is often a strong indicator that your [partner] is not enjoying sex."

Take note if your partner changes the topic whenever sex comes up, Bennett says. While they should definitely work on feeling more comfortable opening up to you about sex, it also won’t be a bad idea to point it out and let them know that sharing their feelings is A-OK.

Everyone’s different, so if your partner has never been one to make a ton of eye contact, a lack of eye contact shouldn't be cause for concern. But many times body language can speak volumes. As clinical psychologist Dr. Josh Klapow tells Bustle, someone who isn’t enjoying sex will likely look away, not return a kiss, or not put their arms around you. It’s their way of participating without really participating.

Both partners need to fully participate in order for sex to be fun and fulfilling, which is why how you feel afterward can speak volumes. So if you leave the experience feeling less than fulfilled, Klapow says it could be due to your current lack of sexual chemistry.

If your partner isn't enjoying sex, they probably won't be as passionate, as caring, or as motivated during sex, and that can result in a lackluster evening. So pay attention to these feelings; if you didn't feel as great as you normally do, there may be a reason for that.

Sex has so many elements, including a connection between you and your partner. If they don't enjoy sex, you'll notice that that closeness isn't there. While you'll never want to pressure your partner or make them feel bad for being disinterested, you can always point out what you've been noticing.

What do you and your partner do before sex to show that you're interested? “Every couple has a 'dance' which occurs when a partner is initiating sex," Dr. Racine Henry, Ph.D., LMFT, a licensed marriage and family therapist, tells Bustle. "Whether it’s a certain kind of kiss or a touch in a particular spot, you know when your partner is trying to initiate physical intimacy."

If your partner isn’t enjoying sex right now, you might notice that they’ve stopped doing all the things they know you like pre-sex. They no longer play with your hair, or brush your leg, or kiss you before bed, all because they aren’t enjoying the act — and thus don’t want to head down that road.

This one’s a bit unique, but you might even be able to tell that your partner sounds different during sex. "We sometimes make sounds to please our partners and help them to reach orgasm," Dr. Jess O’Reilly, Astroglide’s resident sexologist, tells Bustle. Think moaning or screaming your name. A partner who isn’t into it won’t go that extra mile.

On the flip side, Laeta says your partner might moan and yell but they’ll be saying things like “hurry up” or “I want you to come.” It sounds sexy, but the reality is they’re encouraging you to finish because they aren’t having a good time.

Pretty much everyone on the planet has experienced that moment of vulnerability when getting undressed before sex. But when you're with a loving partner, it generally makes it easier. While everyone gets shy or self-conscious at times, a partner who is no longer having a good time in bed may seem like they’re trying to hide or cover themselves up, Hershenson says. They might seem hesitant about you seeing them naked, they may not let themselves go during sex, and/or they may want to get up and get dressed immediately afterward. These are all red flags they’ve got something on their mind.

Any type of distancing maneuver should signal it's time to have the all-important couples chat — especially when your partner seems to be checking out emotionally.

"If you start opening up to your partner and they turn on the TV or leave, they could be putting distance between you," says Henry. "Pay attention to whether a third entity is being incorporated into your interactions as a means to divert the energy and/attention away from your vulnerable moment." It's likely a sign something's up, and your partner actually does need to chat.

If your partner isn’t enjoying sex it isn’t necessarily a reflection on you or the relationship. Physical and mental health concerns, as well as everyday life, can get in the way.

That said, “if they stop texting throughout the day, or if they forget dates you already had scheduled, or if they don’t show caring or affection, your partner could be communicating that they’re just not feeling it,” Henry says.

This is an issue that requires a lot of deep discussions so you can both figure out if you’d like to stick together as a couple. But if you notice any of the other signs listed above, keeping an open dialogue during these tough moments is the best way to be there for your partner, and to get your relationship back on track. Chances are you and your partner can work through it together and start enjoying sex again.