Bait & Switch

A sexual maneuver used during foreplay. While lying on top of a woman, a man slithers his lower body area towards a woman’s chest area, neck, and chin. At this point the woman can take the bait, his penis, resulting in a blow job, or she can accept the switch: a forced titty fucking

The policy used by Bell Mobility to get more money out of their customers. They will *bait* you in with offers of really good stuff, then switch the offers around behind your back, often with the excuse of "that was just a promotion" or "you must have changed it yourself"

Someone who seems to be "God's gift from heaven" at first but as soon as anything becomes official (I.e. Marriage or signing a roommate lease) they suddenly reveal their true personalities (typically incredibly condescending and/or crazy)

the term can also be used for a relationship when a girl or guy "advertises" her or himself as being something s/he's not and in the end ends up being a shoddier "product" -- a lesser person than was originally promoted.
for example a guy might start out being really attentive to a girl he wants to go out with: lots of emails, text messages, dates, flowers etc... and then once the girl has committed to the guy in some way he turns off the attention and hardly ever calls, no more flowers, hard to get hold of etc...

When a fairly attractive woman or man introduces themeselves to a group of the opposite sex in order to get their ugly friend in the door

The process by which a girl procures a free drink from a man at a bar, and then escapes awkward conversation by pawning him off on her friend.

When a girl stops putting out after she's married. Girls will act as though they are sexually liberated and always up for it, then once the guy is locked in they turn into a frigid prude.