there was one where the uke's in love with his best friend and then an incubus shows up with and teases him with his pet tentacle monster if you find it thanks!
I'm really unsure about this, but maybe this one?
http://www.mangago.zone/read-manga/aijin_incubus/
If not, you might want to look through the incubus tag to see if you can find it.
that's it thank you very much!
I'm here bicthヾ(☆▽☆)