Version 1: An offer from another person that you previously found attractive (sometimes in the heat of the moment) which completely changed your mind so that you are now repulsed by them.
Version 2: The strategy of blowing people off at places such as bars by facetiously leading them to believe that you are interested in them and then making an outrageous offer meant to turn them off and make them go away.
Woman: "I want you now"
Man: "I want you too"
Woman: "Mmm, I want to give you a golden shower"
Man: "Whoa, wait, what?...no, no, no-thank you! ...that's a turn off-offer"
Version 2: "I would love to go back to your place and meet your pet land snails; Johnny Depp and Tom Brady, ...Mmm... and in the morning I'll saute and hand feed them to you in bed!
Then tells his friends: "I just gave that chick a turn off-offer she couldn't refuse".