Advice sought

Claire has a little friend who has a big crush on her. And it's been cute. Until the day on the bus when he sat down next to her, and physically restrained her from switching seats. He sat down in the aisle seat, and when she tried to move to sit down next to one of her other frieds, he put his arms and legs up and wouldn't let her go. She got off the bus in tears. So, I've been trying to teach her how to tell him to back the heck off. And it hadn't happened again.

Until Monday. Luckily, one of Claire's friends saw what was going on, and told him that if he wanted to marry Claire, he had to let her do what she wanted to do. He let her move.

It bothers me that this kind of thing is happening. His mom thinks it's cute, and we get the feeling that she's encouraging it a little bit. But we've been creeped out about it, and now it's to the point where I'm more than creeped out. I'm wondering how to teach Claire to tell this kid to get a life and back off. She knows he really likes her, and he's asked me if he can marry her when they grow up (something I responded to with "We'll see" - his mom was standing right there). At this point, I feel like pulling out a shotgun on the kid. Any suggestions?