Dunkirk Evacuation
This is a sexual term referring to the historic evacuation of 400,000 British soldiers from France during World War II. It is when the man ejaculates into a woman's vagina, then sucks all of it back out through her rectal area, then kisses it right back into her mouth.
I almost pulled out. But I didn't! So I had to perform a Dunkirk Evacuation to get those sperm cells out of there and into a safer territory.