Possible to stay friends with ex boyfriends?

Say you've been dating a guy for a little under two years. He's an amazing guy, and he's treated you so well. But you've just started becoming tired of him. You don't find the goofy things he does funny anymore, and everything he does irritates you. You fight all the time over stupid things. You don't know what to do, cuz you don't want to break his heart. Do you think it's possible to stay friends with this person after being together so long and entrusting each other with so much?