So American teenagers work hard to get around the bases when they go on dates, but what do teens in, say, France, try to do? Is there something similar centered around football (soccer), or is it more of a US thing?
To hopefully clarify more than that XKCD does: If one kisses a member of the opposite sex, one is said to have made it to first base. If there is fondling of breasts, that’s second base. Third base is non-intercourse contact with genitals, and a home run is full-on sex (of course, there is considerable variation in the precise meaning of all of these but the home run, but that’s the general idea). The metaphor can of course be extended, but most extensions of the metaphor, you’re going to just have to explain your literal meaning anyway (the extended metaphors in the XKCD strip are in no way standard).
I knew someone was going to link to it sooner or later, so I figured I’d get it out of the way. 
The phrase “sticky wicket” seems ripe with possibilities.
When I was a teenager we occasionally used the “bases” analogy, presumably stolen from American teen comedies. We didn’t use cricket terms sadly, even though it has a silly mid on, a crease, stumps and a sticky wicket.
Other than that we were just explicit: “I got a handful of tit” or “I got two fingers up”.
ETA: you bowled a googly, MEBuckner.
I was certainly aware of the baseball metaphor, and no other sport that I’m aware of has the same sense of progression as baseball does.
I scored…
Japan uses the letters A, B, and C for the various stages of romantic activities.
Well isn’t this a strange one? For such a wordy nation, fond of our literary heritage and deeply in love with euphemism sexual slang, we seem to be quite lacking a metaphor for that.
“Tops and Fingers” (and varieties thereof) is about as eloquent as we get for that. Of course when it comes to full act we have an embarrassment of riches.
When I was a teen in the UK, we used a star system (one star, two stars, etc.) but I can’t remember what the maximum number of stars was (maybe 5), or the specific meanings of individual numbers.
GGOOOOOOOOOOOAAAAAAAAAAAaaaaaaaaalllllll!
“Puttin’ it in the back of the net” always seemed obvious to me.
back in the day: “put the wood to her”… kind of baseball-ish
1° grade, 2° grade and 3° grade that’s what we use. The ‘Goal!!!’ metaphor refers to pregnancy, being an unwanted one an ‘autogol’
Concur. No particular system in evidence in the UK. The terms used might be slang (and obscure to those not in the know), but there’s no rhyme or reason to them.
Bear in mind how rare the scoring is in that sport…
Anyone for tennis?
It does have love anyway.
Yeah, but Love is when you’re not scoring.
Bunt.
Bunt, bunt, bunt.
Bunt.
So, it’s marriage?