How To Babysit Your Rival (Baby SMG4 Oneshots)
GachaWolfieBloom
Three has only seen Four as his ex-rival and nothing else. At least that's what he thought until Smg4 wants to return back to his youth for a new carnival ride and Mario causes Egad's machine to go horribly wrong, turning him into a baby. Unfortunately, Smg3 has to take care of him until the ray is fixed. He thinks this is going to be the worst 24 hours of his life, but little does the bearded man know that he might have grown a soft spot for the little Four with these fatherly instincts of his.
Attention: This is a Papa 3 x Baby 4 duo fanfic based on the episode: Retirement of SMG3. I just want to make it clear that this is NOT a ship fic. Just wanted to make this because I was rewatching the episode and realized this pair is very underrated and deserves more stories.