Dear Alice, Some of the girls at my school talk about how their boyfriends got to first, second, or third base with them.I feel kind of left out because I don't know exactly what they are. Whether you're hitting a home run or striking out, it helps to have the low down on the latest sexual terminology — not just because others are talking about it, but it may be helpful when communicating with potential partner(s).
Just like you did when you were a little kid, and you’d bust out a flashlight under the covers and open a book.
Only now, instead of looking for Waldo, you’re looking for herpes.
And he’s a much bigger national threat than Waldo ever was.
There are, as the top comment on this question notes, four bases in baseball, and these have corresponding sex acts associated with them.
"I got to second base with that girl yesterday." "I didn't think I had a chance, but I made it to third base with her last night." One of the other answers has provided a nice link to the Wikipedia entry for baseball metaphors for sex.