Derivitive of the word gay. Has the same context as saying, "Your haircut is so gay." Use of the word gehy most likely surfaced as people sought a way to circumvent the censorship protocols of various internet discussion forums. Since the sentence "ur gay" would resolve to "ur ***", forum members found out that saying "ur gehy" would successfully make it past the censors while also preserving the context of the connotation. Of course, the admins of those gehy forums have caught onto this and now prohibit any deritive of the derived word. Such targets of this censorship include gei, gae, ghey, and gehehehy.
ur so gehy