A fish pole
Taking someone to a body of water under the assumption of fishing. Since fishing is extremely boring, suggest stiff pole fishing instead. When she asks what that is, show her your own stiff pole and see if she takes the bait.
He took her to the lake but ended up showing her his stiff pole.
He said they were going fishing but it turned into a stiff pole show.
She took the bait and he got her to cum in the lake.