Irish Lesbian Nickname

Alright, listen up, you big dummy! You see, the joke here plays on two things that sound super similar. First, you've got 'Irish lesbian,' right? Then, the answer, 'a gay lick,' sounds exactly like 'Gaelic.' That's the language they speak in Ireland, you know? So, it's a silly sound-alike thing. You probably thought 'lick' meant... well, never mind what you thought, you big lug.