It isn't rare for European men to kiss each other hello and good bye, although in most cases it is on the cheeks and not on the lips. Gangsta rappers, and this term may or may not apply here depending on who you ask, do not kiss each other, lips, cheeks or otherwise.
Gillie Da Kid, the man who claims to be Lil' Wayne former ghostwriter, also claimed "ya kiss Stunna on his mouth bitch." (see the video below of Gillie talking greazy)
Now the good people here at HipHopDX don't take sides or pass any judgement. But we will show you this: