Is about a guy who can shape shift or something and turns into a bike, then the girl he likes?, gets on him, after a while he starts teasing her, and ends up transforming into the girl to make her believe its a dream and that she's fucking herself.

"It's so much easier to see the world in black and white, gray?... i don't know what to do with gray." Garrus Vakarian - Mass Effect 2.

It's not a doujinshi, it was in a monthly magazine /Kairakuten, Megastore or Mujin/ and i think it has 2 chapters but with different title i try search the name.

You can find it in this book : Onnanoko Yuugi - TSF Catalog and the name of it is : Dokodemo Nandemo Transform (Wherever Whatever Transform / Transform into Anything, Anywhere)

Yes, it's Dokodemo Nandemo Transform, thanks!

"It's so much easier to see the world in black and white, gray?... i don't know what to do with gray." Garrus Vakarian - Mass Effect 2.