Ok, I'll get it after 9 or so tonight.

This was my sister's sophomore year roommate, only she was an Orthodox Jew who would have sex with her boyfriend and then immediately schedule a mikvah.

Wait, but, that's backwards! You go to the mikvah before you have sex, not after!

OMG, so happy to be home in my PJs.

You go to the mikvah before you have sex, not after!

Maybe she's setting up the mikvah for the next time she has sex, now that she's used up the last one?

/ no clue about Jewish rituals.

Oops -- I just thought this woman on The Mentalist was from Leverage, but no, she's from Hustle.

OMG, so happy to be home in my PJs.

I just put on outside pants for the first time all day! I may even go outside!

I don't really recommend Outside.

But that is where the (junk) food is.

Maybe she's setting up the mikvah for the next time she has sex, now that she's used up the last one?

/ no clue about Jewish rituals.

Basically, the way it works is, no sex during your period or for a week after. Then you go to the mikvah, then you can have sex again, until your period starts again the next month. (All this is supposed to be within marriage.)

Reasoning for why varies, depending on who you ask. My favorite explanation was one I heard from the rabbi at Hillel when I was in college. There are a few different times that people go to the mikvah. It's usually thought of as a women's thing, since women go most often, since they have to go every month. Women also have to go after giving birth, or having a miscarriage. Anyone, male or female, has to go after attending to or touching a very sick person or a corpse, or after touching the Torah.

There are a few other times, too, but the things that all of them have in common, other than the Torah one, is that they're times when people come in very close contact with birth or death or conception -- lives entering the world and lives leaving the world. These are holy things, closer to the realm of G-d than the realm of people, and thus should be approached with caution. (Not scared caution, but reverential caution, the sort of "this is something special, let it be OK" caution.) The Torah, as the word of G-d, is also in that holy realm -- generally, Jews don't touch the scroll itself with our bare hands. We move it around by the wooden handles, and when reading it, we use a special silver pointer to keep our place, so that we don't touch the actual scroll with our fingers. So accidentally touching it is also getting much closer to that holy realm than people usually do.

Going to the mikvah, then, is a way of bringing ourselves back into the proper place in this world, reminding ourselves that, while there is a world to come and all kinds of holiness out there, we've got plenty that we need to do in the ordinary physical world first.

t edit: this is mostly stuff remembered from what I heard the rabbi say about seven years ago. I might have a few details wrong.

The mikvah itself, by the way, is usually a small sort of pool with some steps leading down into it, but most natural bodies of water are also allowable as mikvahs. It's generally just easier and nicer to immerse yourself naked in an indoor heated pool than in a natural body of water. The rule about the water is that it has to be "living water," meaning either directly from a spring, or from a moving source like a river or ocean, or rainwater. Most modern mikvahs are set up with a cistern that collects rainwater, and a little bit of the rainwater is mixed in with a lot of heated tap water -- that little bit of rainwater is enough to count as living water.