I don't see any dilemma here. He's just trying to show you he loves you. Enjoy it. It would be a good idea to try to get to know his mother better. Most mothers appreciate when another adult cares about their child, especially someone from church. But they may not appreciate it if they begin to feel like they aren't being included in the mentoring. She needs to feel secure in her position as mother and not feel at all threatened that your bond with her son is in any way infringing on her bond with him.

Dakota