Unless you're paying your partner for the dirty (which is illegal in most states), just tell them you had fun. Save the thanks for your waiter at dinner.

Let's turn the lights off.

We all like to feel sexy and shown off. Telling someone you want to turn the lights off is like saying, "I just don't want to look at you." It's a one-way ticket to insecurity and hurt feelings for your partner, both of which will put a major damper on your sexy session. Just don't say it.

Also check out... Top 5 Cringe-Worthy Moments in the... Relationship Lies that are OK to Tell 5 Ways to Take Control in the Bedroom Tips for Keeping the Conversation Alive

If you're not interested in them, be respectful and tell them; don't make them feel unworthy or unattractive. That won't result in a fun experience for either of you.

I think the condom just broke.

If you want to throw your partner into a full-blown panic attack and completely ruin the mood, then say this line. Nothing is more frightening or heart-stopping to a single man or woman than a pregnancy scare, so unless you're totally sure, don't go there.

By the way, this is never a funny joke.