Family doesn’t respect bf

I’m very close to my mom and younger sis. So I feel like they’re both close to my bf too. But sometimes they say things very rude to him “playing around” but still rude. Like my sis says things like “mother f#%er” “stfu” yet she NEVER talks like that to my older sister’s bf or my brother’s gf. And my mom says things like “Wooow way to go!” When he does something wrong with a laugh at the end, and one time he didn’t put a clip on a bag of chips the “correct” way so she talked to him like a child (he’s 24) showing him the correct way to close the chips I told her “don’t talk to him like a fuckin child” and she laughed saying omg I’m just joking. Yet she doesn’t joke with my other siblings bf/gfs like that. So why mine?! Am I overreacting or should they treat him with respect like the others. They hang out with my bf a lot more than the others though so I’m assuming they feel more comfortable around him to say what they want. But is isn’t it wrong?