Cush'n for Push'n
Cush'n for Push'n - the abbreviated and rhyming form of the phrase 'Cushion for pushing', which refers to any 'cushioning' around the genital area of a female, including pubic hair and excess fat, which may provide 'cushioning' when having intercourse.
John: Dude, did you bang that fat chick you were with last night?
Bob: What? She wasn't fat, she just had a little cush'n for push'n, y'know?
Bob: What? She wasn't fat, she just had a little cush'n for push'n, y'know?