I discovered this when trying to rapidly replace an ageing (and vanishing) population.

Drop a female villager onto a male (or vice versa)
Once you get a "going indoors" message, check the villager details of the female. If she's going to conceive the status indicator will already read "Nursing". Now pick her up and drop her. The baby will now appear after a few seconds.

Babies without all that messy, time-consuming "going indoors" stuff

It's probably a mild bug, but a really useful foil to "The Vanshings".

Enjoy

It's not a bug, it's just the way that breeding is designed in the game. Breeding works in a manner similar to the way fish breed in Fish Tycoon - the outcome is immediate. The "going indoors" part adds interest to the game. There are several discussions of this phonomemon in the forum (and some of them are pretty funny)!

Gosh Barabara 06:07am - Don't you ever sleep? It's the middle of the afternoon here!

Could you point me to the relevant threads? (I think the idea of propositioning causing pregnancy is scary!)

I've been accused of never sleeping before. Trust me - I sleep. Oh, sure, I hang out here more than the average person, but I'm not yet to the point that I'm losing sleep over it!

The Village Sim forum has grown so much that it's hard to locate all of those threads, but here are references to a couple of them (of course, as is always the case, the discussion wanders a bit):

Thread one

Thread two

And, if you're looking for just pure entertainment on the funnier aspects of village life, check out the early discussions from the April timeframe - especially those involving Tibby, JustAGirl, and TheVillageIdiot. You wouldn't believe the stories of Tibby!!