Why is he stringing this along? When I'm giving him what he wants.

Ok so hi you guys. I'm sort of having a dilemma and in need of some good girl advice. So about a month ago I started talking to this guy. From jump I feel like I came off very straight forward and to the point about what we have going on and I thought we had a clear understanding of what we were doing. Which is we were building a friendship and not a couple, so to me I took that to mean I have the green light to date other people 👌🏽. So one day I went over his house and my phone just kept receiving notifications from my snapchat and text messages and that's the day it all started this weird connection between us. He from that day on started acting like he just didn't trust me, he would question me about guys and asking me if I was seeing other guys and I told him the truth. I have guy friends, and I do see them. It's hard to explain but what I can say is he does show some form or fashion of being attached. So one day he asked me again, if I was still talking to other guys and I asked back do he talk to other girls and his exact response was " I have female friends,but they don't like me in that way" so I took that answer and swept everything under the rug until I could prove otherwise. So just yesterday I went lurking on Instagram and low and behold I found something. I didn't even try i to argue with him or anything, I can't trust guys so I already figured he could've possibly been up to something.( forgot to mention I left two of my belongings at his place) I simply asked him to just give me back my things and said we could have a friendship but it's like he doesn't wanna give me back my things and I can't understand why.... ladies help me understand