What is he doing and what should I do?

Before anyone gets super upset with what I'm about to say, realize that I too am upset with this and I know it's wrong, but I am a human and we all fall into temptations but I am here to get help so that I don't. 
I work with a gut at work who I think is really cute and funny. Over time I started to like him when I found out he had a girlfriend and two kids. We always talk off and on for weeks at a time. If we wrk together we text for about 2 days and if we don't see each other at work we don't text. We have different schedules and don't always see each other at work.
For two days we worked the same shift and went a and grabbed lunch together. He always complains about not having good sex anymore and always seems to talk to me about it. We joke a lot together so I can't tell if he secretly wants me .
All day at work we spoke together and when I handed him a lighter he asked me to borrow he held on to the hand that was holding the lighter and just stares at me for what seemed like forever and than just let go.
 Here's where I went wrong. I asked him if he could tell me what lingerie I would probably look good in. He told me to send the picture and he didn't reply for an hour. Once he did he said, "Nice. Whoever sleeps with you will be pleased."
After that I didn't know what to text back and he hasn't text since. Does he like me or jus playing games? What should I do?
Again, I know this is wrong, I'm not saying it's not, I just need some guidance from me fellow ladies who I know have been through this before.