Installment One: Pre-marital Sex in Jewish Law: Just Jew It!Everyone assumes that pre-marital sex is not okay. Or that is the common accepted view for most conservative leaning people- not just Jewish. But based on the Old Testament, and other interpretations, that is not necessarily the case. And here is how you do it:
Females:(A) Jump into Lake MichiganNida laws - you need to purify yourself in a mikvah before engaging in such activities.
(B) Don't do family members familySee Vayikra/Achrei Mot, for specifics on who you can/cant see naked.
(C) Make sure beforehand that you don't want to marry the Cohen GadolCohen Gadol being a Cohen who has been annointed (Leviticus 21:10). The Cohen Gadol needs to marry a virgin (Leviticus 21:13-14). The same rules DO NOT apply for Cohanim in general (Leviticus 21:7), it does not say this explicitly, but since it does for the Cohen Gadol, and uses similar phrasing about other people not to be married: eg widows, it is not out there to assume that stringencies as far as not marrying a non-virgin do not apply for Cohanim. They just can't marry a whore (zona) - so don't charge, chalala (woman who is of the seed of a cohen who married someone he couldnt), or divorced woman(Leviticus 21:7).
So pretty much, until the beit hamikdash part 3 comes up, and people figure out how to deal with the whole tame thing, theyre all fair game.
(D) You (female) don't mind giving up silver pieces from your ketubaKetubot typically are phrased something like:
“Amar la lahada betulata (insert name of betula/wife)…” and then go on to talk about how she's worth 200 silver zuzim for being a virgin…
and so, if you change the phrasing, and are willing to give up 200 silver zuzim, then there's no problem.
(E) Stay away from married menLo tinaf. Nuff said.
Males:(A) Stay away from married womenLo tinaf. Nuff said.
(B) Don't do family members familySee above.
(C) No Male CondomsPeople say you shouldn't spill a seed (Genesis 38:9-10). In this case a dude pulled out and it went on the ground, instead of in his sister in law (in order so that his brother could have a son). So, it says that displeased elohim and He slew him. So I'm not convinced that He was necessarily displeased about spilling the seed in general, but most rabbis are. So, no traditional male-condoms for now, but other sources of birth control seem to be fair game (the pill, iuds, patches, etc.).
No, It Doesn't Mean You're MarriedThere are 3 ways to get married:
(1) With money (object of value, eg a ring)
(2) Through a shtar, a contract
(3) By sexual intercourse with the intention of creating a bond of marriage.
A) it doesn't count because you didn't have that intention and
B) no beit din would consider you married, because there were no witnesses (so dont do it in the open in front of two frum guys)
***Other common assumptions have to do with beastiality not being okay, as well as homosexual intercourse. I do not condone beastiality, thats cruel to animals, and so even if it technically says do not lie with one to defile yourself, its still not okay (Leviticus 18:23). So, stay away from animals. If you're female you're fine as far as homosexual sex is concerned (the Bible never specifies otherwise). If you're male, you may want to stay away from the missionary position - just don't lie down -(Thou shalt not lie down with mankind as with womankind; it is an abomination- Leviticus 18:22).
For the record, these are not necessarily my views on how the Torah/Mishna/Gemara/etc. should be interpreted, or how I choose to lead my life. This was done in good fun, and not meant to shove crudeness in anyone's face, or to offend anyone. I do think, that this is an interpretation of these works, however, and I don't think most answers/approaches to these are issues, and textual reasons why these things "aren't okay" are sufficient.