Mikey's too young to be thinking about who he's going to spend the rest of his life with. He should be out making memories, trying new things, and finding himself. Instead, he's always at home, or in a hospital. His eating disorder has taken over his life and his love interest for an unlikely character distracts him from his recovery. Gerard had his own life, his own problems, and he felt that Mikey was mature enough to handle himself. Apparently there was a lot Gerard didn't know about how his brother was feeling.