A yaoi manga where the uke is a working man who wear glasses and the seme is a high school...

A yaoi manga where the uke is a working man who wear glasses and the seme is a high school boy. The uke had sex with his lover (not the seme) who was his friend from school but then when they broke up and the seme and uke became lovers one day the uke came back from work and saw the his ex and the seme kissing infront of his apartment. Before that the seme met the uke's ex in front of his apartment and then he said to him that he will make the uke his and only for him or something like that so the ex smiled and kissed him. But then the three where like friends and seme and uke still lovers?