Did i cheat on my bf? plz help?

it was prom night and this guy was drunk but i was sober ...me and my friends hAD rooms which we shared just the girls....at that time all my friends were drunk...at the end of the night the guy who was drunk decided to stay in our room...i wanted to go sleep and i was sleeping on a pull out bed...all my mates said he can stay and sleep in my bed and for me to sleep the opposite way so my feet are facing his face...i was very tired and wanted to go sleep...the guy pretended to be asleep and i got into bed and didn't think anything what happen...i had my PJ's on and then all of the sudden he started touching me on my :( i kept moving away so he would get the point but he just kept trying it on....and i didn't want anyone to know because they would think i would be bull shitting and be judge mental. i was with my bf for 2 months at that time...i hated that night...ive never been the one to hurt my other half....please tell me if i did cheat on my bf....