a member

Okay so basically im a sophomore in highschool and me and this guy met last year during my freshman year. He is a senior now and we just started texting one day and lowk flirting. I put on my Instagram note "very flirtatious" and he replied to it talking about in wdym type all that right? Well I asked him what he thought and he said he thinks im talking about us, which I was obviously. All of a sudden he just kept getting hella freaky and asking for pics and stuff but he is super nice but only when he wants things. We both care about each other but I think he just wants to use me or smth because I heard he was talking to another girl in his 4th and he said it without hiding it and we gave class together and we have to hug secretly but he grabbed my ass when we hugged today but idk what do you guys think I should do? I care so much about him but he might just want to use me but also before he asked for pics he js asked for a regular one of my face saying he misses me but idk. Someone help please what do I do