i don't have a ton of detail on the kid. somewhere between 18 and 22 years of age, back when he was sort of in college but mostly fucking around, he either lost track of the mother or she knew he wasn't fit to be a father and never told him, but basically he has no clue they exist and have been tracking him down. he's been all over, kind of a nomad traveler who can't sit still for five minutes, so it's been pretty hard to find him.
as far as the tinder hookups, he's terrible at communication and getting back to people, so they'd probably be one-night stand kinds of things where he said the wrong thing or gave away too much uncomfortable information or never called back, kind of ghosted on them or something.