Of course you do; but you want to appear high-minded and above such thoughts to the world, don't you? I thought so. You're not that devious.
A conventional Google search offers no satisfaction. [Was that what the Rolling Stones were singing about? Or was it the frustrations from their Sharona?] No, you got to be crafty in your search. In the true spirit of the times, you must channel the backdoor search engine technique.
It turns out that the basis of the rules, now interpreted very loosely, were drawn up at a gathering of the New England Sorority Pledge Trainers for Purity and Social Improvement (NESPTFPSI) back in 1955. Since people were less often reading newspapers, and this was in the pre-CNN Eocene, this meeting was under-reported.
Actually, the ladies (Don't call them girls; they would open a serious can of W.A. on you even now!) saw this as a logical step in streamlining the courtship ritual. The idea was, to speed the process of getting those errant boys and girls married as early as possible so that they would have a head start in reconstructing the boy-man that they would eventually marry before he got too set in his bad habits. Furthermore, these rules of intimacy were to continue after marriage, but with some flourishes that were not found beforehand. [These backdoor internet sources alluded to the rule that husbands could finally see their wives naked on their tenth anniversary; a rule that was passed despite strenuous opposition from the Connecticut delegates.]
The NESPTFPSI even adopted the simple first base, second base, third base, home plate analogy that is still current today. It turns out that they had their meeting in a hotel that was also used by a visiting major league baseball team. Since they happened to meet for drinks in the lounge, the severe ladies drew upon a metaphor of baseball, a game that had been played and followed by troglodytes in the large cities that they were familiar with.
So remember, no second base before the fifth date! And remember also to support breast cancer research to save second base!
Finally, unless you're a European princess, keep second base covered!