It's driving me crazy...

OK. Few days ago I remembered some manga that I read long time ago but because I don't remember title, author or if it was full manga or just one shot I have a problem with finding it. I have whole situation from manga in my head and its driving me crazy!
Manga is starting that some salesman is getting out of the train on his way back from work and when some guy is catching his hand saying someone else name. After that guy is getting sick because he is drunk, so salesman have to take care of him. After that he's finding out that he looks like this drunk guy's ex-lover. He says that he is OK with sleeping with him while pretending to be this lover because he understands that feeling because he has been dumped as well. After some time in café salesman can hear guy talking with his girlfriend about some gay-man who was his sugar daddy. Because he's talking about our drunk guy, salesman hits him. Of course at the end salesman and drunk guy live happily ever after.
If someone have idea what manga I'm talking about, please let me know.