How can I stop liking him?

It's hard to see someone you had a crush on be with someone else. Even if you are over the crush. It's a lingering remembrance of the crush. I had a crush on a girl for a while, then one day I found out she was engaged. I was like, darn! So I moved on. I can't have her, and that's that. Only, that doesn't stop me from feeling like I lost something every time I see her around. So it's natural to feel the way you are. I don't know if there's any way to stop the lingering feeling. The only thing you can do is to get something to replace the feelings and distract you. Though this only means you won't have the feelings as much. It's really hard to completely wipe out feelings. But the less you put yourself in a place to feel those feelings it will help. And every time you see him and start thinking about him or getting a pain in your chest, tell yourself something like, "I'm over him" or something else to push your mind off him.