Am I justified in being upset about the “jokes” my boyfriend’s grandfather keeps making about my son?

Im pregnant in my second trimester with boy/girl twins and ever since we announced the genders of my babies my boyfriend’s grandfather has been making crude jokes about my sons genitals… he says things like “I bet during the ultrasound the doctor said he had a huge pecker” and “he’s a [last name] boy so you know he has a big pecker” and other jokes like that. I don’t find these jokes funny in the slightest; they make me really uncomfortable and down right mad. I mean who says something like that about an unborn baby?!?! I know these jokes are probably harmless and the man is close to 90 and blind so he’s hardly a threat but I really wish he’d never made such comments about my innocent unborn son. He, along with other people in my boyfriend’s family, have also been rather misogynistic throughout my entire pregnancy such as insisting both my twins were boys because “their family only makes boys” and being disappointed when one of my babies ended up being a girl… but that’s a whole other story. I haven’t expressed my feelings about it to my boyfriend because that’s his grandfather and I don’t want to seem like I’m making a big deal out of nothing.

Am I overreacting? This is weird right? How would you feel if someone was making these remarks towards your baby?

I’m stuck between a place of “they’re just jokes” and “I don’t find this funny at all”

Just want to know if I’m justified in being upset.

If you read all they way through I really appreciate it I know this was a long post of me just ranting and rambling.