We Try to Be Alone in the Pool with My Friend but We End up Fucking My Roommate Nerd, Unexpected Threesome

My friend and I planned an afternoon at the pool. Sunshine, towels, sunscreen, privacy. She arrives in a yellow bikini that leaves little to the imagination, me in a black bikini that marks every curve. We enter the water, caress each other under the surface, kiss each other with our tongues while the sun warms our backs. But we are not alone. My nerd roommate is in the window of his room, thick glasses, video game shirt, looking with a shyness that contrasts with what is marked on his shorts. My friend sees him first, laughs, beckons him downstairs. He hesitates, hesitates, goes downstairs with an awkwardness that I love.