Oh, ktspktsp and I laugh a lot, usually from little funny things that happen... one common event is when our bodies are all sweaty and moving against each other (esp in missionary), and we get little "squelches" (kinda like when you make a fake fart noise with your hands, but we do it with our whole bodies!).
We also bang our teeth together sometimes, when we are really into the kissing... it's cute, though slightly painful at times!
Oh, and when I am going down on him and I am totally into it, and then suddenly the gag reflex happens and I have to get him out of my mouth quick... that usually produces a quick chuckle between us, and then I'm back to work.
Probably the funniest thing that ever happened was when we first got together... a few days after we hooked up, I got my period. But we still wanted to try having sex standing up (towards the end of my period, when I thought the flow had stopped)... so he was holding me up against the wall while we had sex. We were going at it, enjoying ourselves... but in one moment when he had pulled me away from the wall, we noticed that the wall had red streaks all over it!
(I know, gross.) It was hilarious. We cleaned it quickly and laughed our asses off; can't remember if we even finished that session, it was so funny.