Sitting down with him and talking is a very big thing, but that’s already been mentioned. I think you also need to treat the problem in the scene not just out of it. Now I don’t know how you play but you laughing is maybe somehow being received as something negative on his end. Hearing people laughing and hearing people laughing after you have tripped over a minuscule crack on the sidewalk are two different things. Perhaps he views something about himself as worthy of ridicule or maybe he’s just self-conscious about it and automatically thinks you’re laughing at that. Think of some small ways you can package that laughter so it’s taken in the spirit it’s intended. “hehe you’re such a cutie” or gentle caresses of fondness while you laugh for a couple examples. Or at least do it in such a way so he won’t take it as something directly related to whatever is bothering him (for example, saying “You’re such a sorry excuse for a man!” while you laugh might be a bad thing). It might not be completely natural but it will help build that trust. Trust that the laughter is indeed why you say it is and not a bad thing at all.