a delicious drink made by mixing grape juice and vodka sometimes ginger ale is added in the mix to give things a kick. Its name comes from the fact that mormons cannot drink liquor so for a nice surprise slip ur mormon friend some "grape juice" then tell them what it really is and SURPRISE!
Mormon: this grape juice is delicious
Guy 1: That's not JUST grape juice it's vodka too!
Mormon: *spits it out*
Guy 1: SURPRISE!
When a man dressed in his fancy Mormon underpants sneaks into his sweetie pies bed and lies in wait for her to arrive and give her the "Mormon Surprise".
Jacob snuck into his sweetie pie Mary's bedroom wearing only his Mormon underpants, he crawled into bed, clapped off the lights and waited, when Mary returned home and got in bed, Jacob gave Mary the old Mormon Surprise. Mary was very happy and slept soundly.