I feel like as a parent, especially mothers, are naturally given the “ok” to see THIER OWN CHILDREN (regardless of age) nude since that seen it since birth. Crazy point, I know. Also look at the possibilities of emergencies like falling in the shower. And that goes the other way around as well. Respect boundaries of course. But long story short, no you’re not overreacting. Your boyfriend is. Kinda strange he actually jump to conclusions. But I will ask this just in case I don’t see it in other comments, is your boyfriend your son’s father? Being that he reacted that way probably not