FWB....!

I wanna be FWB with this guy that I used to date. I’m a virgin but idk I still have a very strong sexual attraction to him. But when we did date we were kinda sexual but not to point where we had sex. Like I’m 15 and he’s 14 and we’ve watched porn together and he’s masturbated beside me so I feel comfortable with him. But idk I have talked to him in over a week and I kinda hint that I wanna be FWB like I post sexual memes and shit on my sc story but block everyone from seeing it but him. And I just don’t wanna message him straight up and get rejected so idk how to ask.