I'm not exactly sure if this manga was a yaoi or not. I only read the first volume and I cannot remember the title for the life of me as it was several years ago and I randomly found it in the library but I'll do my best to describe it.
The premise is that there are two rival straight men. They are both good looking but one sort of idolizes the other. I can't remember if they are both athletes or actors or one of each though I'm positive they were most likely athletes. The more popular, confident playboy offers the other man a one-night stand after he is confessed to. He tells him he can never return his feelings and to leave him alone after the one-night stand. After they have sex, the playboy leaves the other man crying in the shower. That's all I remember. If anyone knows the title or similar manga, please let me know.

The worlds not perfect, but its there for us trying the best it can. Thats what makes it so damn beautiful