Currently on a big family holiday with 3 of my siblings (we're all parents aside from my youngest brother) and one of my other brothers was desperate to go go-karting. Despite being told by me and others in the group we'd go at a more appropriate time (we were actually on a trip out at that time) he fucked off anyway leaving behind his pregnant wife and child.

When I seen him later in the evening he was saying he planned to come out to dinner (while his wife stayed back and cooked) with the rest of the group and I told him that he shouldn't be going anywhere after leaving his wife and child like he did earlier in the day. He stormed off without saying anything.

My mother was trying to mediate the situation and said that I was out of line butting into his relationship because I don't know the dynamics and that it's not my place, that I'm just making the whole holiday awkward for everyone etc.

My SIL married him so she knew what she was getting into, but did I overstep my bounds?AITAH?