was it molesting?

Kelsey
So about 5 years ago I guess, when I was 16. My moms husbands friend that he worked out with who was mental(not completely, he could drink a few beers and stuff but still had a care taker). Was obsessed with me. He told told me he liked me a lot and all this, buying me stupid little necklaces and stuff, like he thought I felt the same about him. At one point I was helping cook at my moms house and he was there. And he wanted a hug so I gave him one and he was asking me if I liked him and this and that and I kept saying no, I have a boyfriend and I'm 16. I'm to young, which he proceeded to touch my butt and try to put his hand in the front of my pants and touch me, I kept telling him no, and he in return still did it.i was scared and could barely move. Finally I yelled at him and all he said was please don't tell on me, please don't tell on me. As he was all close to me still trying to touch my Butt. So I told my mom and her husband and he yelled at him and everything, anyways. I'm just wondering if this was technically considered molesting? Even though some people laughed because he is mentally retarded. Or said he didn't know what he was doing. But he did... he told me not to tell on him. Doesn't that mean right there that he knew??...just trying to put this behind me.. as I finally told my husband about it.