Is my boyfriend's family normal

My boyfriend doesn't talk a whole lot about his family. In fact whenever anyone in his family calls he always says to tell them he's not here. And his family is really nice to me but they seem to intentionally embarrass him or make jokes about him. Whenever my boyfriend and I are over there they feel the need to tell me things about him that embarrass him. Like his mom mocked how he sucked his thumb well into his teens. Telling me he was a crybaby and they can never say anything to him without him crying. And they only do this to him. Not his siblings. His siblings actually join in. My boyfriend never really says anything when we are around his family and they all criticize everything he does. First they claimed he worked too much. Now he's at the moment a house husband and they criticize that. We went out to dinner with them last night. My boyfriend really wants to lose 10 pounds so he just ordered a chicken salad with blue berries, avocado and some like humus. He was trying to eat a bite of avocado and his mom smacked his hand and said "I think you've had enough". Then it got really weird when they told me another "embarrassing" story and laughed about it.... But this story was flat out uncomfortable. They asked if my boyfriend ever told about how he got this nickname penis flicker at his daycare. I didn't say anything but they told me anyway and my boyfriend looked so uncomfortable. His whole family told me about how when he was 8 he went to daycare during church(it was really just Sunday school). He ended up telling his 2nd grade teacher that one of the older kids(16 or 17) would make him pull his pants down at church school and the teen would flick his penis over and over again until it hurt. It obviously came back to that church and the teen could no longer allowed to go to the younger kids room and they started calling him penis flicker at daycare. Everyone was cracking up except me and my boyfriend..... Maybe it's just me... But that seems like an inappropriate story to tell very loudly at a restaurant and laugh about.... Whenever I asked my boyfriend was he ok he changed the subject. He never talks about his feelings on his family or how they treat him.