Why does this guy keep coming back knowing how I feel about him and knowing he doesn't feel the same about me?!.. I'm confused.... opinions?...

Here's a little background -

I fell for him, he hardcore flirted with me, telling everyone I was his 'girlfriend' but then he turned around and told everyone he wouldn't date me cause of the age difference.. we stopped talking, like a year later he came back... he got what he wanted....(we had sex) I told him again that I still have feelings for him.. he left.... now he came back again...? Why?! He knows he's not getting the 😸 again.