The United Colors of Monogamy

Eternal
You choose a sexual/marital partner for life, but think the statement "until death do us part" lacks conviction. If your partner dies before you do, you figure you're not supposed to have sex ever again in this lifetime. (a.k.a. "Swan").
Lifelong
Fidelitous with one partner for life, but if your partner dies, you might consider dating, marriage, and sex with someone else... eventually (a.k.a. "Strict" or "Practical").
Gender Restricted
Close friends of the same sex as your partner are avoided, discouraged, or prohibited (a.k.a. "No Window Shopping").
Gender Unrestricted
Close friends of the same sex as your partner are permitted or even encouraged (a.k.a. "Modern").
Asexual
Having no sex with your partner whatsoever (a.k.a. "Gold Watch" or "Twenty-Year Man and Wife").
Autoerotic
Having sex with your partner only, but also masturbating (a.k.a. "Pr0n").
Serial
Fidelitous with one partner "for as long you both shall ... feel like being together". Partners may be switched out as often or as rarely as the mood takes you (a.k.a "American").
Enhanced Serial
Same as the preceeding however fantasies, crushes, and other forms of flirting with people aside from your partner are just innocent fun, and so are also okay (a.k.a. "No-Touch-y").
Alternating
Switching between two (or more) partners over any period of time, but "faithful" to each one while with them (a.k.a. "Polyamorous").
Discreet infidelitous
Having affair(s) which you successfully hide from your partner (a.k.a. "Business Class").
Indiscreet infidelitous
Having affair(s) which you fail to hide - or make no attempt to hide - from your partner (a.k.a. "Classy with a Capital-K").
One-sided
Being in a relationship with someone who has affairs (discreet or indiscreet) while you yourself remain faithful (a.k.a. "Martyr").
Scene Specific
Participating in kinky scenes with people other than your partner, which, whether they involve you having sex or not, are separate from real-life, so technically it doesn't count (a.k.a. "Play-Doh").
Romantic Hopeless
Loving people other than your partner without doing anything physical with them, so TIDC (a.k.a. "Asexually Polyamorous").
Opposing Gender Specific
Having flirtations, sex, or even relationships while still in a relationship with your partner, but only with people of not of the same sex as your partner, so TIDC (a.k.a. "Bisexual").
Monoamorous
Having sex with people other than your partner but not actually loving them, so TIDC (a.k.a. "Swinging").
Giving Only
Performing manual or oral sex on someone aside from your partner, but since you're not the one receiving the pleasure TIDC (a.k.a. "Do Unto Others as Long as They Don't Do Unto You").
Recieving Only
Receiving manual or oral sex from someone aside from your partner, but since you're not the one doing the "doing" TIDC (a.k.a. "Clintonese").
Old World Traditional Male
Having discreet affairs, because everyone knows one woman can't possibly satisfy the sexual appetites of a real man (a.k.a. "Soprano").
Liberated Female
Having discreet affairs, because everyone knows one man can't possibly satisfy the sexual appetites of a woman in her prime (a.k.a. "What He Doesn't Know...").
Autoerotic, Clintonese Discreetly Infidelitous, Monoamorous Opposing Gender Specific, Enhanced Serial ... Monogamy
Monogamous, except for masturbating, or receiving manual or oral sex from someone of the same sex as your partner while successfully hiding it from your partner, or having sex with someone of the opposite sex from your partner but not loving them, and taking a new partner as the mood suits you, and fantasies, crushes, and other forms of flirting with people aside from your partner are just innocent fun, and so are also okay (a.k.a. "Delusional").

Inspired by "The seven definitions of monogamy" by Eric Francis (www.ericfrancis.com).