In love with the boss

(NOTE: sorry for the length and my errors I'm typing this on a phone) I am a senior in high school I got my first job at a grocery store. A few weeks working at the store I meet one of the co-managers. He did not work regularly, but at the time he had to, so I saw him quite often. Most of the time on my shift everyone I worked with was males. So every chance they got they would flirt with the customers. Or they would joke around with me. I began to notice the manager taking interest on me, and it wasn't just games anymore. One day he asked for my phone number, and I gave it to him. Please keep in mind he appeared quite young, ( mid twenties ) and I did ask if he was single and he said yes. At the time I was a virgin and I wanted to give it up to a responsible, respectable man, with no feelings attached (had a bad break up, didn't want to fall in love). So I thought he was the perfect guy and we had sex. A month later he comes to the store on his day off with his whole family, pregnant girl and friend kids. I confronted him, and he acted like he was innocent as if I never ask if he was in a relationship. Another month goes by he is still flirting, texting, asking if we could do it again, and I continued to say no. Keep in mind he was my first and last at the time. So one day I give end we have sex for the second time. After this I was feeling guilty because I knew this time, but I had a connection with him that I never had with a guy. I wanted that to be the last time so every time he would text me(not often) I would tell him no. Like two months later we do it for the third time, and to be honest I feel attached. I'm not the type would let guys in in any way, especially physically. So with him being the only one who I have let in its hard to let go. The last time I found out he is actually in his early thirties, which means his lies never stops. I know I am in the wrong too, I'm just trying to get out of this situation. Although they are not married I'm ruining a family right now. I'm hear for advice please help me if you can and thank you in advance.