The deckchair sex position is termed this way because the lovers having sex in this position bring to mind a deckchair. This sex position is also called the lounge chair position. The man sits on the bed with his legs straight and spread shoulder-length. He leans a bit backward and plants his hands on the bed at his back.
The woman faces her lover and sits in between his thighs. And then she leans backward until she is lying on her back in between his legs. The woman raises her legs and places her calves on top of the shoulders of her lover. She places her hand on top of the thighs of the man.
This position allows the woman to stimulate her clit while her man enters and exits her vagina. She can help with the pace by lifting her bottom up and down, or rotating her pelvis evocatively.