Ok, so they have a rule saying men can't have sex with their wives on their period. Seems sensible enough, but of course they take it to extremes. Instead of the woman just deciding for herself when her period starts and ends, a rabbi has to decide. In order for him to know, she has to wear a white cloth in her underwear and bring it to him to examine. If there's any stain, odour or discolouration... no sex for another week! It's like some kind of pervy groundhog's day. There's also some weird rules loopholes about adultry, so her husband could potentially be out chasing chiksas while his wife is at home hoping the rabbi will be pleased with the sniff of her panties this week.