Actually you know there is a very real strain of thought in ritualistic magic (here, on Earth) that sex and sexual activity drain one’s powers and thus the most power wizards/witches etc should remain celibate.
This also similar to the line of thought that magic takes lots of energy and that a fat wizard is a powerful wizard and a skinny wizard is a dead wizard.
Meaning, a wizard should eat a lot of food, store up energy in the form of fat, and as they cast spells, they burn the fat for energy.
Thus you start a wizard battle at 300 lbs and end the battle having lost 200 lbs.
I’m pretty sure I’ve read books with this sort of theory, I just can’t think of which ones.
Although, to be honest, Trisfelt insists to everyone that this is true for Thaumaturges, which is why he’s so portly. However, I don’t think too many people believe him.