Got grinded on at a concert

I 18m got grinded on by a lady who looked about 30ish and it was one of the best experiences of my life. It started because I got far up in the pit and it was crammed so I was already up behind her and I have poor balance so I kept bumping into her on accident and once the music started we were all moving and then she starts backing up on me which I thought was an accident so I just stood there until she did it again so I let it happen until I started to get hard and then I pulled away because I got scared she would be upset but slowly she kept rubbing against my hard dick and there was no way she didn’t know because I could feel my dick going under her ass every few seconds and she would occasionally kinda bend down like she was looking for something but she wasn’t I wanted to get closer to her so bad but we eventually got split up because the pit kicked up and I didn’t see her until the concert ended