The Rainbow Grind is a gay coffee shop that first appeared in the episode The Real Book Club.
Pat took Kenny to The Rainbow Grind as his first LGBT social place, ever since he came out. There, Kenny enjoyed his first time at a place like that, and Pat met up with Zack, an old friend who had recently come out as gay. Due to a miscommunication in their conversation, Zack was led to believe that Pat was gay too, allowing him and Kenny both into their LGBT group of friends.
Kenny and Brett went on a date at The Rainbow Grind in the episode The Real Acceptance, where they officially became boyfriends. On another one of their dates, Brett told Kenny that he loved him, in the episode The Real Confirmation.