A family-friendly synonym for sexual intercourse. Appropriate for school, work, and church.
Steve: "That was a great sermon... how was last night?"
Me: "I had my ace in the hole. It was amazing... but certainly not as amazing as Christ's love for us."
Principal: "Good morning Miss Daisy, how was your date with Mr. Rodman yesterday?"
Miss Daisy: "Oh, he's such a handsome gentlemen. We finished with his ace in the hole."
any thing advantageous one keeps hidden until the right moment to use it. This is a play on playing cards, in which the Ace is the highest ranking card.
"Viagra was my uncle's Ace in the Hole with this girl last night. Ugh... -_-"