I feel like he's a spy or smth sent by the organisation who made the Beomhae in order to keep an eye on whether the dads are actually taking care of the kid or not. (Idk if that makes sense but thats my theory lol) but I totally agree with you!! He seems kinda fishy lol.
The kids friend gives me bad vibes but maybe that’s just me? Seems a bit too aware if that makes sense