Not everyone is always in the mood for sex. But what happens when you do it anyway, just to "get it over with?"

A moment like this sticks out in "Cat Person," a new film based on the viral New Yorker short story (in New York and Los Angeles theaters Friday; nationwide Oct. 13). College student Margot (Emilia Jones) feels like she needs to sleep with Robert (Nicholas Braun), an older man she meets at the movies, after a less-than-ideal date. We watch her discomfort: She doesn't want to go through with it but aims to avoid potential awkwardness.

Experts warn having sex should never feel like something you should just "get over with"; communication is key to make sure all parties are comfortable and satisfied.

"Everything is wrong with the decision to have sex to just get it over with it," says Vanessa Cushing, licensed professional counselor. "It annihilates genuine connection and authenticity, it subverts desire and it reinforces dangerous gender roles that lead to female sexual oppression."

'The wrong reason to have sex'

This type of situation is not uncommon, among both individuals and couples. But why?

Some may feel pressure from their partners or put pressure on themselves. Society conditions women to this in particular, that they must please a man in order to keep him: "A woman might 'get it over with' because she feels anxiety that her partner might leave her if she doesn't perform," Cushing says.

Those in long-term relationships may feel they need to have sex as a form of maintenance. This isn't inherently a good or bad thing. "Sometimes having the willingness to have sex, or the motivation to have sex because it's important to your relationship or it's important to your partner isn't necessarily a bad reason to have sex," says Ian Kerner, a therapist specializing in sex and relationships. That said: "To just have sex because you feel a pressure to have sex or an expectation to have sex, that's the wrong reason to have sex," he adds.

Plus, "getting it over with is the active decision not to choose yourself and your pleasure," Cushing says. "I see a lot of women after many years of 'getting it over with' or 'having sex for my partner' not feeling any sexual desire at all."

Moments like this can feel wrong.

"While it is a decision cognitively to have sex to please your partner or to 'get it over with' your body doesn't know the difference," Cushing says. "Your body still feels like this is something it doesn't want to do ... If you do not want to have sex, honor your body."

More on maintenance sex:What is maintenance sex and when does it become a problem?

Create a safe environment to talk about sex

Cushing's advice? Don't have sex if you don't want to have sex; this means a frank discussion with your partner or partners. "The biggest thing is creating a safe environment where you can talk about these things freely and it is not awkward and sexual assertiveness is celebrated," Cushing says.

Remember, too, that the definition of sex isn't black-and-white, or all-or-nothing. "Maybe it's about switching up the definition of what sex is supposed to look like," Kerner says. Non-penetrative options like oral sex may better line up with someone's wants or needs in a given moment.

Conversations about sex may feel odd, but that's because "we live in a sex-negative culture," Kerner adds. "We live in a sex-avoidant culture, we've never learned really how to talk about sex. It wasn't really modeled for us."

No time like the present − especially if you notice your partner isn't vibing with your quest for sex at a given moment. "If you can tell that your partner doesn't really want to have sex with you and they're just doing it to get it over with then you should probably not have sex with them," Cushing adds. "I always advise having a conversation and checking in with the other person and seeing how they are feeling and what they are thinking."

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