It’s said sex is like pizza: Even when it’s bad, it’s pretty good. But that’s not saying there’s not always room for improvement. But should you tell someone they’re bad in bed?

If you want to keep on having sex with someone who can use some tutoring in the bedroom department, you have no choice but to guide them in the right direction. Mediocre sex can always be improved upon, but not if someone doesn’t know what is happening isn’t working.

“If you’re looking to achieve positive outcomes (e.g. change in future behavior), I recommend you shift the conversation from “you’re no good” to “this is what I like”,” says Astroglide‘s resident sexologist Dr. Jess.

The bottom line is that no person is universally good or bad in bed — it’s all a matter of personal taste.

“If your lover isn’t giving you what you want, try these one-liners: I love it when you… (Even if they’ve never done exactly what you’re describing, they’ll likely take credit and follow your directions.) I’d like to try… I need more of ________ to reach orgasm. What can I do for you? Is there anything you’d like me to do differently? This opens the door for your partner to reciprocate with similar questions,” says Dr. Jess

1. Start With The Positive

Make your request. Conclude with another positive, says Dr. Jess. If you’re in a long-term relationship that you want to stay in, the trick is not to tell them they’re bad in bed (and bruise their ego forever), but to play up and praise what they’re good at, says sex expert Dana Myers.

This way, you’ll get more of what you enjoy and less of the moves that turn you off. You might say something simple like, “That thing your’e doing feels amazing… More please, more!” Then, when your lover goes back to the move that makes you cringe, you’re better positioned to just say “Oh babe, do more of what you were just doing! I want more!”

2. Don’t Overwhelm Them With Requests

Start with one or two at a time, says Dr. Jess.

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3. Don’t Start The Conversation Right Before Or After Sex

Make a mental note and bring it up at another time.

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4. Give Constructive Criticism

“Instead of saying “you’re bad in bed,” make suggestions about what you want them to do to you, what you want them to do more of, less of, and what’s not you “favorite” but you love when they do this instead,” says sex expert Laurel House.

If you directly criticize your lover, he/she may be on edge in all areas of your sex life, not wanting to “make a mistake” or “do the wrong thing.” House says if you love oral sex, for example, but he/she lacks the right moves to get you off, say “It’s such a turn on when you go down on me. I love the way your tongue swirls around my clit. It would be amazing if when you were doing it, you slowly press your finger in and out of me at the same time.

That would turn me on even more!”

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5. Cut Your Losses

If the bad sex is a deal breaker, and you’re ready to get out of the relationship because of it… AND you feel compelled to tell them that’s the reason why, Myers suggests going simple like, “I just don’t feel we’re sexually compatible,” or “Our sexual chemistry just isn’t right, and that’s such an important part of a relationship… so, we just can’t continue on together.”