Excuse for why i can't hang out with him anymore?HELP!?

He's 20. I'm 16. We already made out like 3 or 4 times. I cheated on my boyfriend with him.(made out and hung out with him behind my bf's back) I've never been alone with him and never want to. I don't know why, he just gives me a bad vibe. He called me today and i accidently picked up my phone cuz i thought it was my best frined calling, i know. i'm stupid. I don't have a problem with hanging out with him with my friends there i guess, just don't wanna be alone with him. So he tells me he wants me to see his new apartment. And he misses me, and blah blah. And i didn't kow what to say so i said i miss you too. When i don't AT ALL.I don't wanna see him ever again. I don't know how it happened, but i gave in to him picking me up at my house in 4 hours, taking me to his apartment, making me dinner there. I honestly think he's going to me. He's creeepy. He's like " yeah, it'll be great, just me and you, don't you think?" and i was like"umm yeah. i gota go, i'll call you when i'm ready