Aaww! Feelings!

Que dulces y que rápidos ellos non pueden tiempo

Loved it.

"It would be just a matter of time before they resumed their adulterous activity."

Adultery only occurs when one or both sex partners are married to other people. Their activity wasn't adulterous (even if it *was* adult!) if neither one is married.

If neither one of them is married at all, not even to each other, then the technical term is "fornication," but that word is a bit outdated. Few people even know what it means anymore.

In this case, I would change "adulterous" to just "adult" and leave it at that. "...resumed their adult activity."