g is a full for for guy. This is mainly used (always) when you address somoni who you are "grateful" of or when you want something. This is a slang used in Britain a lot. (Please the way many Americans use this makes me cry, please use it when you know how to. Applaud American's who know how to use this)
" I like your cut g" , " Ay wag1 my g" , "my g" , "pass me the ____ g"