Am I just a filler until he finds someone else?

My ex and I have been friends since we broke up over a year ago. I keep on dating here and there but haven't found anything special and he is doing the same. We talked about crossing that line again and that's not were we see ourselves, well mostly he doesn't see himself in a relationship anytime soon. We really close we talk and talk about things that worry us and about pretty much anything on our minds. We can go out to dinners, movies, stay in and watch movies and have a WONDERFUL time. I started falling for him more and more due to him acting as a boyfriend instead of friend these past few weeks. Holding my hand while we're walking, cuddling me even if we're just watching TV, kissing me just because.. SO here is the question... Is he falling in love with me? Or he is just using me till he finds the next girl?