Oooooo … I like that one. That one is going to get some use 
I am actually a big fan of the phrase “enjoying the physical act of love.”
USAGE:
“So, Scrappy, where’d you get the black eye?”
“Well, so-and-so and I were, shall we say, enjoying the physical act of love, when in walks her dad…”
Heh. My college roommate and I both dated girls one year behind us in school.
After we graduated, we both moved to the Big City that was 40-50 miles away from the small-town college. The college, as a service to students, subsidized a bus service between the campus and the Big City.
So, for us, we used “riding the bus” as a code phrase because every time we rode the bus to visit our girlfriends who were still at college … we got laid.
Mrs Sarclmbr and I use “Pouncing” and have since we started dating. . . . don’t remember exactly where we picked it up but it has served us well 
Courtesy of Reinhold Aman’s book, Talking Dirty:
to dance the blanket hornpipe; the buttock jig; the cushion dance; the married man’s cotillion; to dance to the tune of the shaking of the sheets; to dance with your arse to the kipples
to go quim-sticking, rump-splitting, working the hairy oracle
a bit of business, curly greens, androgynation, a bedward bit, a goose-and-duck, a shot at the bullseye
to play at houghmagandie (my personal favourite)
I could go on, but there are 12 pages. Terribly funny book, though.
I’m surprised that none of our Dopers from across the pond have suggested “having a bit of slap and tickle” or however it is that the expression goes.
While I have always enjoyed “making a deposit at the bank,” my all-time favorite comes courtesy of Bobby Peru in Wild at Heart:
“One-eyed Jack’s yearning to go peeping in the seafood store.”
Oops
Sorry, didn’t read page 2 before replying
Duke got there first.
(and PE is still using it)
rumpy-bumpy?! I am a brit and i’d have to say that i’ve never heard that used before! certainly the most common phrase in the UK is “shagging” - for sure.
fancy a shag?
Now THAT’S funny. Although I am sure the Lovely and Talented Mrs. Shodan would not get the 1984 reference.
We refer to activity of an intimate nature as “quality time”. From when the children were younger, and when the door was locked, Mommy and Daddy were having “quality time”, and should not be disturbed unless someone was bleeding or on fire.
Regards,
Shodan
That’s our usual outcome.
Zensters’ Aardvarking brings to mind something I got from the old alt.peeves news group. ‘Makin the sign of the eight-legged aardvark’.
I can’t believe no one has mentioned “canoodling” yet.
Dam woman didn’t I give you sweet lovin just five minutes ago?
Chef said it and it’s written on my socks today.
Cabaret, maybe? At one point Fritz is asking Sally’s advice on how to woo a virgin and she advises to just pounce. He does and Natalia slaps him silly. Natalia later is complaining to Sally, saying “I don’t know what got into him.” and Sally responds surprised, “My goodness. He pounced.”
DD
I like rumpy-bumpy, myself. (but who doesn’t…)
Terms I have used:
Playing Scrabble. When I would call my best friend in High School and he would answer the phone during the dirty deed, he would say, I’m playing scrabble, can I call you back? If you got a triple word score… well, you can just imagine.
Rump-humpin’. Um… for the ‘back door’ variety.
Cleaning the Beaker. For a BJ. This then turned into a Muppets reference and was never again the same.
uh…??? Horking means vomiting. Some people also use it to mean eating very fast (horking back your food)… but the standard definition is that one horks up one’s lunch.
Me? I like “having sex” or “fucking” myself.
What about “Wanna get lucky?”
Although I’m not too sure just which of us is the lucky one…
I’ve been known to refer to it this way too - “I was running on time this morning, but then Mr zoogirl got a bright idea and I hit work twenty minutes late! :D”
** FilmGeek: ** Why in the world would your friend answer the phone during sex? Maybe it’s just me, but, if I’m enjoying the physical act of love, everything else can wait.