Open Question: Is this a normal thing to do when I'm mad?

Ok, well I've always wodered WHY I do this.. This is what I do.. When my dad and I get into a heated arguement, and he's about to explode into a million pieces and I feel like I could fall off a cliff and not feel scared, that's how mad we are. When we are THAT mad like imnnot een kidding kinda mad, and we start yelling at each other and stuff, no matter where we are, I always end up laughing. I'll give you an example, cause most of you are probably confused: ok so one time me and my dad were fighting (I'll tell you why we always fight lol) so we were arguing my dad was yelling and I was calling him all kinds of names and sayig stuff like "ok, whatever" "and you think I care...?" and rude stuff like that. And then once I say something that my dad can't answer back too so we just stare at each other with intense "I-would-kill-you-if-I-could" looks on our faces.. My dad looks like some super mad guy with anger issues while I probably look like a girl who has a "I-don't-care-your-wasting-my-time" look mixed with a "god-I-hate-you" kinda look lol! Soo we are staring back at each other super super super mad at each other. And then I burst out laughing.... It's so random. I try hard not to laugh, I can litteraly FEEL the laugh surfacing up. I try to stop it but I can't. And I'm still mad. Then my dad starts yelling again, and I just laugh harder.. It's soooo weird. And my parents think I'm doing it on purpose, when I can't even stop it!!!! What's wrong with me? Is this normal for a 12 year old girl? It only happens to me and my dad, even when I storm off to my room, after arguing with my dad, I still laugh, only with my dad though, the reason why we fight is usually cause he thinks it's "cool" to act like a cool "hip" dad. And I think it's annoying and you get it lol. Is this normal? Being sooooooo freaking and suddenly laughing until tears roll down my face? Please help lol. It happens with my mom rarely, we barely argue. Haha help. Thank you, from a weirded out 12 year old girl