A sex act that two or three people do while having sex. One person lays down flat on their back, while the second person cums on the first person's face. After ejaculating on the face, the second person sits on the face. This causes the spooge to smear all over his/her buttcrack, buttcheeks, or butthole. afterwards, he/she continues to pleasure the first person to finish the job.
Guy 1: "Holy fuck! You gave her the Liquid Seat last night after prom? That's disgusting!"
Guy 2: "Yep, but it felt good once she started licking my asshole once I sat on her face."