Bowser has only one son?

[Cobalt Blue]

but come on, it is obvious these were called siblings to actually avoid any kind of explanation such as "with who did bowser make out in order to have children" or "is there a Ms Bowser?"

that is basically how you managed side characters in the 80's-90's.

its like trying to make some sort of canon as to who are mario and luigi's parents, seeing they were basically spawned out of nowhere.