This happened a few years back. But I (33m) have a large group of friends for over a decade from when we were teenagers working at a restaurant. One of these friends, I'll call her Sam for the sake of the story, I always had a connection with but the timing never worked out. She or I always had someone else. 10 years later our entire group is at a bar we would frequently close down. That night her boyfriend drank a little too much and her sister, who was sober, volunteered to drive us all home and drop me off on the way. We got her boyfriend situated in the front seat and I sat in the back with Sam. As we got out of the parking lot Sam groped my leg near my crotch which instantly got me hard. I leaned forward in the gap between the seats and made small talk with her sister as a distraction and slipped my hand between Sam's legs. She was wearing leggings and I could feel how wet she was through her pants. As we drove home Sam took my hand and slid it down her pants to her soaking wet pussy. This drove me crazy and it wasn't long before I could feel her quiver and cum on my hand. I continued to finger her until we got to my house and I had to hide my hardon as I said goodnight and went to the garage. That night I jerked off while sucking her juices off my fingers.