what i know is that the uke went to a resort to get away from someone and met the seme and he was showing the uke around the beach and other places and end up having sex at the beach while the person the uke was trying to get away from calls while the uke and seme were having sex on the beach and the seme continues not caring who is on the phone and the day comes where the uke has to leave but he fell in love with the seme.

Chikan Diary maybe the Chapter 3?