I bow to superior knowledge. 
Gettin’ some poontang.
Similar but not the same.
I’ve heard “dropping the kids off at the pool” used for #2 but the kids/swimming reference definitely infers boinking.
As Bessie Smith put it:
*I need a little sugar, in my bowl,
I need a little hot dog, between my rolls
You gettin’ different, I’ve been told,
move your finger, drop something in my bowl
I need a little steam-heat on my floor,
Maybe I can fix things up, so they’ll go
(spoken: Get off your knees, I can’t see what you’re drivin’ at!
It’s dark down there!
Looks like a snake! C’mon here and drop somethin’ here in my bowl,
stop your foolin’, and drop somethin’, in my bowl)
*
or, as the holiday season approaches:
Santa Claus got stuck in my chimney, stuck in my chimney, stuck in my chimney.
Santa Claus got stuck in my chimney when he came last year.
Wham bam, thank you ma’am
inspecting ceilings
Knocking the dust off
Making the beast with two backs
Affirming the relationship.
Regards,
Shodan
Did you mean “Tube-steak Boogie”?
Consummating the relationship.
Slippery friction of mucous membranes
Appeasing Mr. Gray
Carrie Fisher called it “Surrendering the Pink.”
Post 3.
Poke her yoke.
knocking boots.
Gettin’ laid.
Gettin’ naughty
getting a bit of strange
(Just learned from an Australian friend).
bumpin’ beneath the bedcovers
There’s the Dirty Sanchez…