This is when a man is so consumed with getting ass from his girlfriend, it's all he can think about. He's "blind" to everything else around him, because in his mind, he just wants that pussy or "puss." Symptoms of "blinded by the puss" include not picking up the phone when your boy's call (because you are with your girl), not wanting to do anything but nest in the house with your girl, buying your girl anything and everything she wants, catering to your girl's schedule at ALL times, and always being on call for anything your girl wants to do. You basically become a variation of a zombie (only doing what your girl wants you to do). This is a variation of "pussy whipped."
Dude # 1 : What's the deal with your boy not wanting to hang out anymore?...That guy used to be awesome to hang around...what gives?
Dude # 2 : Dude, he's so "blinded by the puss" that he can't think straight anymore.