The process of switching from one female to the other through sexual intercourse. Whether it's oral, anal, or vaginal, the females must be on each other or close by in order to complete the switch back fast enough.
Sarah and Tina were laying on top of each other kissing, while Jim was preforming the switch back on both of them.
A snatch back is defined as a GF or wife who is bitching out their boyfriend or husband so intensely, that the man ends up having a sore back....., or otherwise referred to as a snatch back.
My GF was rippin my ass out harshly over the fact that I spent the night before out wit da boyz at the 02 watching the fights and after a while, she was being such a snatch, ridin my ass so bad that my back started achin brutally. The chick actually gave me snatch back. S'up????