boner
A DICK FULL OF EXCITE
Person 1: "There's going to be a surprise but I'm going to not tell you until it's too late!"
Person 2: "Dick."
Person 1: "A dick full of excitement!"

Person 2: "So you're a boner?"

OR

Person 1: "What's a boner?"
Person 2: "A dick full of excite."