Livingstone T Lion and The Creeper used to be gay lovers before their falling out.Livingstone talks about how The Creeper "broke his heart". Also, we never see Livingstone nor The Creeper show any romantic interest in any female character. This could also explain why Livingstone tried to reconcile with The Creeper in one episode as he still had romantic feelings for him. Also, the reason we're never shown a flashback episode about Livingstone and The Creeper is because of their strong homosexual relationship and the fact that Animalia is a kids' cartoon.
WMG / Animalia