I don't know if he's gay/bi or not and it hurts

So I've been talking to a guy for a few months now and he said he was straight from the start but whenever he snapchats me he's just "horny" and asks me to send nudes back to him just for fun. He insists that he's straight but he asks to see my d*ck a lot? We flirt so much and talk for hours and I'm slowly falling for him but if I ever mention anything about hanging out or meeting he brings up that he's straight and would only ever be friends. I'm so confused and I keep getting my hopes up and then I'm let down.