[–] 18425676? 0 points 1 points (+1|-0) ago 

So they won't enjoy sex, thus being less likely to cheat.

[–] 18428137? 0 points 0 points (+0|-0) ago 

[–] 18425784? 1 points -1 points (+0|-1) ago 

Its probably a preislamic practic that survived.