Graphic kissing. I don't want to draw sex and I don't think I would be able to do it even a little bit well, but not wanting to draw graphic kissing is more funny for the thread.
Kissing is gross and that's where babies come from and I don't want to draw people who's tongues are touching.
(just to be more clear, I am perfectly fine with drawing cartoony, simplistic, or just not graphic kissing. Just don't expect it to get French)
And obviously nothing offensive, but again that's not funny.