IDIOMS

wet dream

(idiomatic, by extension) An exciting fantasy; a very appealing, ideal thing, person, or state-of-affairs.

Example: 1985, David Lewis, "British playwright makes a mountain out of a Mole" (review of The Growing Pains of Adrian Mole by Sue Townsend), The Globe and Mail (Toronto), 9 Jan., page E22:
  His mother is having an affair with the man next door, is reading Germain Greer's The Female Eunuch—which spawns Adrian's first wet dream.
1986, Liam Lacey, "Same old irresistible Seeger," The Globe and Mail (Toronto), 24 Oct., page D11:
  Bruce Springsteen may become middle America's wet dream.
2007, Addy Dugdale, "Betavoltaic Battery Could Power Your Laptop for Thirty Years," gizmodo.com, 2 Oct:
  The plan is, if all goes well, to have these batteries, an eco warrior's wet dream due to their non-toxicity, on sale in two or three years.