Responses
Its this one. :)
http://www.mangago.me/read-manga/kuchibiru_ni_amai_doku/
There's also a sequel.
http://www.mangago.me/read-manga/netemo_sametemo/
It's really this one, thanks a lot xD
I forgot the name of a yaoi that has the art very similar with this one http://www.mangago.me/read-manga/binetsu_no_karute/ , they are two singers and the name of one of them is Yuu.