It started as a joke. I went out with my aunt to help her choose a new car but we came across her ex-boyfriend who dump her a few weeks ago and she introduce me to him as her new boyfriend, and I played along, start to kiss her, touching her as a real boyfriend while they were talking, this made really horny and I guess she felt it against her legs and liked it too. Later she started to invite me to go out more often and we end up, after a few dates, at her place.