My boyfriend gets on me about my weight! And is mean so I picked on him about going bald?

I am 25, my boyfriend is 43. We had a baby 4 months ago and I am trying my damnedest to get the weight off. I'm dieting and my dr. even put me on phentermine which is helping. It's coming off slowly but surely. Mean while my boyfriend has been a jerk to me about my weight! I don't wanna mention all the things he's said cause it makes me sad but he's been very rude. After enough arguments he's stopped making those comments and started being a little more supportive, I guess cause I'm trying so hard. But he still does this thing where if we're watching a show on TV he'll say something like "Wow so-n-so lost SOOOO much weight!! Thank GOD cause she was a fat *ss!! Or if we're around a friend of his or mine he's say "Wow you are SO thin! Look how skinny she is!" So I've tried to handle this the mature way but now I wanna have some fun! My boyfriends hair is thinning, a lot! And he has a bald spot in the back. It honestly doesn't bother me because I love him but he's very self conscious about it. So last night we're watching a movie called Fighter with Christian Bale. In the movie the character has very think hair, just like my boyfriend. So I say "Oh MY GOD!!! Is Christian Bale's hair really that thin!! If it is I'm gonna have to KILL MYSELF!! Good GOD I hope that's a fake piece!!" All dramatic like! So he get's all bent out of shape "That's HIS REAL hair! I've seen him in a lot of movies with his hair just like that!!" I said "NO Christian Bale has a thick luscious main! That is NOT his hair!" I could tell this made him upset but I wanted him to have a taste of his own medicine. Was I wrong or is this funny as hell! Lol! I mean really? He should be so lucky cuase I can lose weight but he's not growing hair back any time soon and I never give him a hard time about it like he does me!