What to do about an unloyal friend?

This guy, I met in 9th grade. We became decent friends. Were in grade 12 now, and we have good fun hanging out, but now it's like I'm his last priority. He only pays attention to me when he's not around his other friends. I ask him to hang out and always says he has plans, only rarely does he accept, and he's not even that busy of a person. So he only really talks to me, when he's alone, and when we are hanging out, I feel this incredible pressure to entertain him, and make him laugh, even though he hosts.

I'm the kind of guy that lets people walk over me, stab me in the back, and I'll forgive and forget and let it happen again. Should I put more effort into this friendship? Or should I dump it? If I should dump it, how should I do it?