Anyone knows this manga?

I have been trying to find this yaoi or shounen ai manga (I am not sure which one it is) but I didn’t find it till now, it’s about a man who doesn’t have pubic hair and is sad about it (I think) and he goes to high school then his classmate somehow knew about it and was trying to tell him that it’s ok (it was something like that) then he showed him his penis and it’s small. I don’t remember after that I read it a long ago and want to read it again so if anyone knows about this please tell me