Just because nintendo SAYS the Koopalings aren’t Bowser’s kids, doesn’t mean they aren’t his kids. You can’t have a bunch of kid underlings and NOT just instantly be their father. Even if it’s not biological…. BESIDES, it’s canon that all babies come from storks in that world, let the man just have a horde of babies because the stork won’t STOP SENDING THEM.
Maybe each koopaling wasn’t technically Bowser’s kid but little bastards that none of the Storks wanted to deal with so they dumped them at Bowser’s every time because they kinda look like him and so they can be his problem and Bowser just rolled with it.
… I mean why else would they have their own rooms in some versions of Bowser’s castle, their own airships and castles with their names on it if they ain’t special to Bowser in some way? Petey Piranha doesn’t get that kinda treatment.
You get it. You’re a keeper.
And, being Bowser, he probably doesn’t even question any of it, questions are for nerds. Except possibly how did “Roy come pre-packaged with sunglasses?” because let’s face it, he probably did arrive like that.
being Bowser he probably did a little doubletake and then muttered “That’s a cool baby…” in a sort of alarmed tone