I have a feeling that if Bowser and Dr. Eggman joined forces, Bowser Jr. would meet Sage and he will feel butterflies in his stomach, and kinda simping for her
Not one for shipping kids (Unless it's a hypothetical future type thing) but I think it would be cute if in a new Mario and Sonic crossover if Bowser Jr. keeps trying and failing to impress Sage because he has a crush on her or something