FWB or dating-how not to get hurt in the process

My friend introduced me to her friend 3 months ago. we chatted, i like him, he said he was too busy w/work and not looking for a rel. then 3 weeks ago he started texting, we talked, he came over, spent the night. I am early 40's he is late 40's, I've been married once, div. for 4 years, had an LTR for 3 yrs. He was married 2x, div for 2 years. I feel this amazing connection and chemistry, like i did with my husband and long term bf. I have gone on many many coffee dates looking for a good guy. Now i believe i have found him but he has made it clear that he wants FWB for now, maybe more later. i am ok with that for a while but I know myself and I know I will gt wrapped up in him emotionally and feel connected, and I dont want to be hurt. I think he is hesitating for a rel. b/c his ex cheated on him and he is afraid of being hurt again. He is texting, asked me for coffee yesterday, actually it feels like we're in the early stages of dating, he has asked me to do things. But I dont want to misinterpret. He said he wants to be friends and if we sleep together that's great but if we dont that is fine, too, he wants to know me as a person. I could see myself being with him long term. I am holding back emotionally and also not getting too deep with him when we talk, but he seems like he is interested. How do i continue-without being crushed? He is not a player, he is a great guy. Give him a certain amount of time (without telling him) until he says he's ready to commit, or just back off with spending time now, or what?