One of my classmates has a 1 year old that she had last year before our program started. I'd heard that it was an "oops" baby with her boyfriend. For background, I also knew from talking to her that her boyfriend was also Jewish and they have been together since college (so 2.5 years at least).

We had a departmental event and she brought her child and the man I thought was her boyfriend, since he was in her profile picture. He was also wearing a Yamaka so I doubly thought it was her boyfriend. Now here's the thing, her baby was clearly half black, and this dude was just as white as she is. I was curious so I facebook stalked her and found an old profile picture with a black guy who looks just like the kid.

I wasn't trying to start shit or anything, I didn't say anything to her or the guy obviously, especially because the kid was with them. I asked a group of other students, who I'm friends with, if her boyfriend was sure the baby was his, as a joke. The girls in the group got really upset with me and told me that the guy was her brother and the black guy I found on facebook was her boyfriend. They accused me of "jumping to sexist conclusions." Again, I wasn't trying to start anything and I didn't say anything to the girl and it's not like I could've known the guy was her brother, I was just making a joke. The girls in the group won't talk to me now and I'm worried this is going to start a whole thing if they tell the girl what I said. AITA?