Is it a red flag in a man if he has his first relationship at 24?

The man who wants to be in a relationship with me hasn't had a girlfriend since highschool, though he says she doesn't count since it was highschool, so id be his first real, serious girlfriend. (He's had a few small things in-between but none progressed to a relationship. I'm the first he brought home to meet his mother also ) Is it common for a man to have his first serious relationship at this age? Or is this a red flag like maybe there's a reason it's taken this long?
First relationship at 24 is normal
Red flag
Select gender and age to cast your vote:
Is it a red flag in a man if he has his first relationship at 24?
Post Opinion