Looking for a oneshot

So, all day I've been looking for a yaoi I read a few months ago that I didn't save. So the plot to the story is a little weird, just to warn you. So the MC has a big dick, so it's hard for him to keep a partner, so he gets depressed and decided to go smoke in front his apartment. At that moment his neighbor comes out with a man, the mc calls him a slut or something and they argue and then something happens and they switch bodies. I don't know what exactly happened after that, but I do remember that they switch back and the MC ducks his neighbor and then the the neighbor revels he has a big duck to then ducks the MC. So they become a seke couple in the end I guess. Thank you if you can help me !