100% obvious that you're right and that she is cuckolding your friend.
BTW, one thing is trying to fuck my wife, another thing trying to supplant me as a father "unofficially". That's casus belli and would probably lead to great violence. Just saying.
The caveat is that hes gay, but it still is in the disrespectful camp for me
Gay or not, you don’t discipline other people’s kids
I guess that depends on what you call discipline. If it’s a one off comment when the kid does something terrible, that’s probably fine. But if it’s lecturing about something or more physical, then def not ok. Give a ride is probably fine. Fixing things up - nah. Why? Let the guy handle it or pay someone.