Yes, a couple of times. First, at a club I went to when I was in college. Went with my best friend, who was also my fuck buddy in high school. Went to the bar to get our drinks and some guy, who was like 45-50 and looked like a major perv, grabbed my ass, rubbed it and held on to it. He says, "I'd love to eat your ass." I told him not to ever fuckin' touch me again. When I returned with the drinks, my friend (who is built like a football player) sensed I was pissed and asked what the guy had said to me. I told him and he said I'll take care of it. I asked him not to, but he took off. After watching them argue a bit, the older guy left. I asked my friend what he said to him. He said I told him if he ever so much as looked at you again, he would be looking up at the ceiling for a very long time. My hero...lol.
Another time I was on a second date with this guy, and we had finished dinner, drinks and watching the entertainment. We left the restaurant a little tipsy and outside, with people going in the restaurant and traffic going by, he keeps grabbing my ass and junk. I got a little hard. I later found out he was married, with kids. I was surprised he was so daring in public, and in a very small town. However, I should have known. During the entertainment, I went to the bathroom to pee, and he followed me. With someone in a stall on the end, he grabs me and pulls me into a stall and starts kissing me like crazy. I wanted to stop but to this day, he is hands down the best kisser I have ever had. I seriously melted.
As someone said, there are many kinds of gropes. For me it was the one you don't mind or want to happen, and the other one from someone that was unsolicited, and was just plain creepy. Hope I never experience that one again.