Can he and I just be friends?????

Do you believe it's possible to be just friends with an ex fwb without any flirting. Do you think he and I can just be cool!? I would love to be his friend, he's an awesome guy. He and I haven't 'fooled around' in like a year and a half and I'm not planning to. I highly doubt he wants to hook up because he has a girlfriend as i have a boyfriend as well. Okay before you ask 'why would you want to be friends with him if you have a boyfriend?' The thing is he is my mom's best friends son and well it's hard to avoid him. He is coming to my house tmrw and well im back home for the holidays so I will be seeing him. Okay well it didn't end bad but it didn't end well either. He basically just one day decided to not talk to me anymore. Which initially hurt obviously but I've forgiven him. So I don't see why he would be upset with me...it should be vice versa. But im over it, because I've got an amazing boyfriend whom I love. He and I never were 'official' per se. We were more like Friends With Benefits.