Of course I have. Many times. Sex should be fun!
Sometimes it's just a playful frolic with lots of laughing. Sometimes it's rough and aggressive.
Sometimes it's a very serious business.
As long as it's enjoyable for all participants, go for it.
There's laughing when something's funny - which a lot of people do, sure.
Then there's laughing due to an endorphine rush - which apparently not as many people experience. Some people have these intense high-low endorphine rushes and it can result in off-putting things like crying or laughing (offputting if the partner isn't aware it might happen).
Sex is adult play - moving towards climax and those ultimate highs can be accompanied by so much playfulness, teasing, whatever works for the two involved in those glorious moments of foreplay. Movement towards climax doesn't need to be a direct line. Make the time, spend a couple hours with your special someone... Experiment - fail miserably, laugh uncontrollably; try again - ah... bring out the chocolate sauce or nutella - spread it where the fun is heightened... ah, come on, y'all know how to use your imaginations here, right?
I had a boyfriend in 2008 who used to make me giggle during sex. My giggles would get him extra hard. So while I didn't fake giggle, I did look for opportunities that would make me giggle and thus arouse him. He said that a woman so thoroughly enjoying making love with him that it caused her to giggle joyously. was very sexy. And I agree with the comments of others, my giggles would be mixed in with moans, s, sighs, sporadic breathing, and happy little contented purrs.
One time I was hitting it just right and this girl kept queefing and laughing all hard about it. I looked her right in the eye and told her that if she kept farting like that I was going to stick it in her ass.
I was able to cum in peace and quiet shortly after that.
One time I started laughing because for some reason we were not in synch with each other's moves like we usually were. My wife at the time dead panned stared at me and asked "What's so funny?" I laughed a little more as I was explaining how we just couldn't synch up. She rolled over and said that there is nothing funny about sex, and went to bed.