Noun: A scenario designed, staged, or influenced by a man or lesbian for the sole purpose of snaring a specific woman. A trap for any woman, rather than a known individual, is known as a Pit Trap.
"So why are you baking a cake for Kristina's party, dude?"
"Bro, come on, it's a Venus Womantrap. You think I do this for fun?"
"John's party this weekend is totally a Venus Womantrap - there's no way he's actually in to Sex and the City."