In the U.S., "gaywad" is slang, used mostly by kids and teenagers as a pejorative noun.
Calling someone a gaywad doesn't mean you think of them as gay.
A gaywad might be just an irritating, socially awkward person, or more specifically, they might do something or like something considered inappropriate for their gender.
Calling someone a gaywad can show a joking affection, or it can be intended cruelly.
I don't know when "gaywad" was first used, but I learned the word in 1980, in Texas.
Variants include dorkwad, bitchwad, and fuckwad.