Pam and her five sisters, n. — Green’s Dictionary of Slang

Pam and her five sisters n.

[pun on Pam/SE palm]

the hand as an agency of masturbation.

2003		Sonia AliveandBlogging.com 8 Sept. [blog] To call someone a ‘tosser’ is to suggest that they have an overly intimate relationship with Pam and her five sisters.
2004		P. Howard PS, I Scored the Bridesmaids 214: It’ll make a change from Pam and her Five Sisters.