What my boyfriend did has caused a lot of drama in my family

My post may sound a little familiar because I posted about this situation with my BIL months ago. I don't remember know my BIL because when my sister married him she was in a different state and we never really all hung out. My sister and her husband moved down here and when we all got together her husband pulled on my 14 year old son yo make him sit in his lap. When my son went into the kitchen my boyfriend followed him and my sister's husband's mom was angry because she heard my boyfriend tell my son not to sit in his lap. It started a lot and my sister's husband wanted to fight my boyfriend. My boyfriend was sexually abused as a child so it makes him more sensitive to this stuff and my son was sexually abused by his father when he was 3 but luckily doesn't remember. I get what my boyfriend was trying to do. It's just caused a lot of tension. I had my boyfriend apologize but not much has changed.. I did try to explain my sister my boyfriend's POV because after all we don't know her husband like that and my son doesn't really know him at all it does seem weird to have a boy sit on a grown mans lap he doesn't know. My sister called me a bitch and the drama has gotten worse than I thought it would be. My family is upset about it and my dad told me things like that is how innocent men get labeled as pedos. I feel everyone is overreacting because my boyfriend was private how he told my son and it was my BIL mom who made a scene and then my BIL making a worse scene and trying to fight my boyfriend over this. I feel alienated from my family and I'm not sure how to make everything right or what else my boyfriend can do. He apologized. I'm not sure what left to please everyone. My BIL said the only way he will let this go is if I dump my boyfriend.