Need some advice with a guy

Hi guys, I've been having a sort of dilemma recently. I've been getting crazy mixed signals from this guy and I just don't know what to do about it. Short summary: we're both in high school and we see each other quite a bit. He would send me snaps saying things like "ily" and when I sent them back, he continued on like nothing was ever said. He is also very touchy and would grab on to my upper thigh when sitting or arm when talking. He also is known for saying random things and I've heard him say things like "I suck dick for fun". While all of this would suggest that he is gay, he always says he isn't when asked and claims he makes out with girls all the time. I just recently started sending him some signals back, I would touch him like he touches me and I would send him more romantic snapchats (without being too obvious). As soon as I started doing this he began to withdraw from me. He stopped checking the snaps I sent him, only responding once a day and would ignore any question I asked him to try to start a conversation. In addition, it seems like he might be avoiding me. I want to do something but I'm just completely lost in what I should do about it. Have any of you experienced a similar situation and if so, what do you think I should do about it?