Should i delete my friend off facebook?

We've been best friends for 5 years i used to date him but then we broke up and decided it would be better just to be friends. But in grade 12 he dropped out of school because he really liked me a lot and didn't want to see me. Now we barely even talk and i feel like we aren't close anymore and i can't trust him anymore. He stalks my facebook i know this because he "liked" all these old messages on my wall and pictures. Then we added one of my friends that he doesn't even know just because he wrote on my wall. Now i feel like he's stalking me a lot. But we've been best friends for a long time and now hes acting weird. Should i just delete him for good? I tried to talk it over with him before but he Still just keep stalking my facebook.