There's a glossary of terms... I swear to god, I'm not making this up.

The New Monogamy - Marriage With Benefits:

"Above-the-waist rule
An agreement that any touching above the beltline is fair game.

Body-fluid monogamy
When a couple forgoes the latex with each other but requires it for all outside sexual activity.

Celebrity trading card
As seen on Friends: an imaginary laminated card in your wallet—proof that your partner has given permission for you to sleep with the stars listed.

Cheating
Secret, extracurricular romantic and/or sexual activity that breaks the rules. So nineties, so lame.

Closed relationship
How some people in open relationships refer to “old-fashioned” monogamy.

Don’t ask, don’t tell
A policy whereby people in a committed relationship may screw around, so long as they are discreet.

Ethical slut
A promiscuous person who strives to approach partners with respect and honesty. (From the 1997 how-to book by Dossie Easton and Catherine A. Liszt.)

Fifty-mile rule
You don’t sleep with anyone who lives in your city. (Also the title of a 2002 book by Judith Brandt.)

Make-out party
Events open to the public where semi-nudity and above-the-waist fondling are encouraged.

Open flirting policy
An understanding that flirting is healthy, harmless fun.

Open relationship
A long-term, committed relationship in which the couple explicitly agrees to extracurricular sexual activity, either together or individually.

Party bisexual
A woman or a man who engages in same-sex sex-play after multiple martinis.

Pinch hitter
Someone a couple brings in to spice up their love life, e.g., to watch them have sex or to get together with one-half of the couple while the partner watches.

Physical monogamy
You can look, fantasize, and engage in dirty talk— but no touching.

Polyamory
A philosophy of being involved with multiple long-term, intimate partners.

Polyfidelity
Having more than one long-term partner but being closed to additions, e.g. trinogamy (see below).

Polygamy
Multiple spouses.

Swinging
Partner-swapping. Sometimes referred to as “the Lifestyle.”

Trinogamous
To be in a committed threesome.

Work boyfriend/girlfriend
A colleague —your lunchmate, IM partner, smoking buddy, etc. No sex, though."