Does he feel something for me or am I being used?

I met this guy 3 yrs ago and we dated a few times. I have some abondonment issues so when I first met him I was very clingy. Forward two years -we have had tiffs,started the **** buddy thing,have stopped talking,and started back up with a friends with benefits relationship. I do not want a relationship, and dont even want to date right now. He wants his freedom to sleep with who he wants, after being married 20 years he decided he wants to experiencing sleeping with a few woman. I am ok with that.. I went through a divorce after along marriage ,so I know where he is coming from. Anyway,we are friends, but he told me last night about a girl he slept with ,and she wants a relationship. He said he doesnt want a relationship but she does. I ask him if she knew about me and he said no. I told him I would not be a third party and he said if he ever does get into a relationship. (if it just happens with someone he meets that he feels a real attraction for) we would quit having sex. He wouldnt feel comfortable cheating. I ask him point blank; why he hangs out with me ,and he said the sex is great,and we have a great conversation. I am also about 50 lbs over weight. 35 lbs of that I gained since I met him. He is kind not to say anything about my weight but we do talk about it if i initiate the conversation.. I truly believe he is a good guy. Sex between us can get pretty kinky I told him i will not have a threesome until i lose my weight. And the incentive is working. I have lost 13 lbs....The bottom line is I think he is open to a relationship with someone and just not me. But why did he call me (After not talking to me for two weeks) right after he had sex with another woman.. He has helped me move furniture,he is a computer tech and always helps me with computers. Also I text him from time to time ,and he doesnt always respond, and I can deal with that. But if he text me, if i dont text him right back,he thinks I am not talking to him. I am confused what does all this mean.