For six months last year I had an FWB. We met on a casual relationship website, went for coffee, got on well so started going to each others place for movies and sex. Then he started staying over. We were never exclusive, however I knew he wasnt married or living with anyone (spent time at his house).
After a few months I was getting too attached to him so told him I had to stop. He seemed quite gutted, said he would miss me. I was quite resolute not to see him again but we would text jokes or chat every week or two.
Six months later I had a bad short term relationship. I chatted to ex FWB about it and he was really lovely, supportive, came over, sent flowers, we started having sex sometimes again. Then increasingly his messages have become very adoring, loving. Hes told me how happy I make him, how special I am, how he is attached to me.
I've refused to have sex but he still wants to see me, he said he wants to be friends forever. Then tells me he has feelings for me. But he hasn't asked me to stop dating 
Sorry it is a bit of a mess! Does this sound like someone trying for sex or should I offer him commitment? Or just carry on as we are and see what happens?