Hi everyone
I just remembered yesterday about a yaoi manga that I read a while ago.
It was about a guy who had pretty weird dreams about his friend where they had sex, except his friend was made out of some kind of weird substance so he could pierce through him with his hands etc. he had sex with his palm for example...
In the end it turned out that his friend was having some kind of astral projection out of body experiences and he was consciously visiting the guy in his dreams to seduce him. And his physical body ended up with many scars after this.

I'm pretty sure this was a oneshot manga, but I can't seem to find it in my vast collection ┐('～`；)┌
The downside of having too much yaoi...

Shisei no Otoko chapter 5-6 (Spring Love, Dream's Guidance)

Thank you so much! ^-^ I wouldn't have found it by myself ♥