Partnered sex (and all the things you might say and do during it) is nothing if not personal. After all, you’re totally naked, getting literally intimate with parts of a person’s body that typically don’t see the light of day. But because of long-standing societal stigmas around sex, pleasure, and orgasm—not to mention the inherent vulnerability of having sex—there are a few phrases and behaviors that universally tend to, well, rub people the wrong way in bed.

Up high on the list of what you definitely do not want to say or do during sex is “anything that could invite defensiveness or insecurity around a topic that is already quite fragile because of the way our culture teaches us about sex,” says certified sex therapist Casey Tanner, LCPC, CST, founder and CEO at The Expansive Group, a queer sex therapy practice, and sex expert at pleasure-product company LELO. For instance, a person who might feel embarrassed about a certain kink due to pervasive cultural narratives could be all the more triggered by a sexual partner dismissing or shaming that desire.

Through years of experience working with clients, Tanner has come across a handful of things that everyone should best avoid in the bedroom (or wherever your sexual pursuits take you). Read on for what they would not ever say or do during sex to keep everyone feeling good from start to finish.

What a certified sex therapist would not say or do to a partner during sex

1. Say, “You always do X” or “You never do Y”

Just as “always” and “never” shouldn’t make their way into relationship arguments, they’re also two words to steer clear of during sex. These absolutes are almost always (sorry) an exaggeration and come off as attacking a person’s character, rather than critiquing a particular behavior.

As such, these words often spark defensiveness, says Tanner. The person will be tempted to come up with a time that they actually did do the thing you’re claiming they never do (or a time they didn’t do the thing you’re saying they always do). And that discussion will go nowhere fast.

“Just putting out, ‘You always do this,’ or ‘You never do this,’ doesn’t actually tell your partner what it is that you’re looking for.” —Casey Tanner, LCPC, CST

Instead, Tanner suggests avoiding big, overarching statements and being as specific as possible when offering feedback in bed. “If you’re going to make a complaint, make sure you’re showing up with ideas, too,” they say. “Just putting out, ‘You always do this,’ or ‘You never do this,’ doesn’t actually tell your partner what it is that you’re looking for, either. So, it’s also helpful to be as specific in your requests as you are in your feedback.”

2. Use any pet term for one of their body parts without checking first

Assuming that you’re communicating your needs and wants in bed, you’ll likely find yourself in the position of addressing someone else’s body parts. At which point, it’s best to go for anatomical terms (e.g., clitoris, penis) unless you’ve checked with a partner and gotten their okay to use any other word.

A person’s body parts are a component of their identity, and in the same way that you wouldn’t address them by a word with which they don’t identify, you don’t want to risk calling one of their body parts a word that doesn’t vibe with them, either (like, say, pussy or beaver), says Tanner. “Pet names for body parts are words that some people really love and others really hate or find to be a turn-off or dysphoric, so I would always ask before introducing a term for someone’s body that you haven’t used before.” It’s best to do so in a separate conversation about sex, rather than in the middle of a sex act, they add.

3. React defensively to a request for a vibrator or lubricant

“Because of the ways we’re socialized around sex, many folks believe that if you’re ‘attractive’ enough or if you’re good enough at sex, then your partner’s going to be able to lubricate on their own, and they’re not going to need lube or a vibrator to have sex or to orgasm,” says Tanner. But that’s just completely not true. “After being in this field for a while, I can say definitively that the way the body lubricates isn’t always in proportion to how turned on the person is,” they say. “As a person with a vagina, you can be very turned on and dry or very turned off and wet, for example.”

As a result, there’s no reason to react defensively if a partner with a vagina asks for lube or a vibrator during sex; it doesn’t mean that there’s anything wrong with your appearance or performance or theirs, says Tanner. “It just means that there are outside tools that you can use to enhance the sexual experience for everyone involved.” To think otherwise or resist the use of either tool upon a partner’s request is to risk them having sex that doesn’t feel good, is less orgasmic, or is potentially even painful, says Tanner.

If you still find yourself feeling resistant to using either tool during sex, work to educate yourself around why a partner might want to use lube or a toy, Tanner suggests, and consider the potential benefits for you, too. Then, once it feels organic, try reacting to any request for lube or a vibrator with eagerness, or even inviting it yourself. “Maybe you’re the one who asks a partner if they want to use a toy instead of them being the one to ask,” says Tanner. “It can be a really powerful experience for your partner to feel taken care of by you in that way.”

4. Ask to use less contraception once you’ve started getting busy

Consider the case closed on contraception decision-making once sex has started—unless you’ve decided that you actually want greater contraception, says Tanner. “If the shift you’re wanting is toward less contraception, that is not something that you should ask for in the middle of sex.”

Amidst the hormonal flurry of a sex act is just not the time when you can expect a partner to make a decision that could potentially have long-term implications (like pregnancy or a sexually transmitted infection). “In that scenario, they could end up making a choice that feels authentic during sex but doesn’t feel good after, or they might feel pressured to make a decision that they’re not comfortable with,” says Tanner. As a general rule, keep the conversations about contraception before sex to ensure everyone’s comfortable with the potential consequences.

5. Leave a mark on their body (without consent)

Just because consensual partnered sex puts you in the unique situation of getting up close and personal with someone else’s body does not also imply that you can leave a mark there—unless you’ve gotten express permission to do so. “Without asking, you can’t know what a partner’s experience is around marks, hickeys, or any sort of pain during sex, and you also don’t know what their plans are later that day or week,” says Tanner.

That’s all to say, a hickey shouldn’t ever come as a surprise to someone. “If that’s something you want to do to a partner, check in about that by saying something like, ‘Would it be okay if I left a mark here?’” says Tanner. “That can be before sex or during sex, but either way, it should be a conversation.”

6. Say “ew” or express disgust

As the saying goes, it’s never a nice idea to yuck someone else’s yum. “People already have enough shame and guilt around what they enjoy sexually due to societal narratives,” says Tanner. “Making any expression of disgust around something that a partner finds pleasurable during sex could only heighten the shame or embarrassment they may already feel.”

If your partner is doing something that turns you off, Tanner suggests communicating that in terms of “I” comments (like, “This isn’t something that I enjoy” or “I don’t like it when…”) rather than making a blanket statement about what is or isn’t okay to enjoy or want during sex.

“The reality is that if there’s something sexual that is consensual, there are people out there who enjoy it, and that’s great,” says Tanner. “So, it’s important to remember that your negative feelings about a partner’s sexual behavior—whether it’s a kink or a power dynamic or something else entirely—are about you and not about the thing itself.” And any response you have in the moment should reflect that reality.