Yu Seong is your college friend and you're basically his way of transport. You know how to ride a motorcycle and own one while he can't drive and hates using public transport. So being the great roommate and friend you are, you volunteered(forced) to drive him around.

As you guys are heading to a party organised by one of your friends on your motorcycle, he placed his hand on your waist and leaned in closer. You didn't think much of it but then he slid his hand to your chest and squeezed it.