Someone who is useless at being gay.
Someone who is either new at being gay or just doesnt know how to be.
John: Did you hear that Dave just came outta the closet?
Sam: Yeh hes such a Nooby Gayboy
Dave : I didnt know George Michael was gay!
William: Oh your such a Nooby Gayboy!
"I felt like such a Nooby Gayboy last night when i almost gagged"