There was this really old guy at an old-timer's dance, and the problem was that he hadn't had any sex for a long time. He'd been dancing with all the grandmas all night, but still hadn't scored.
Frustrated, he approached an old grandma and said, "I'm having no luck scoring a woman. How about coming back to my place for a roll in the hay? I'll give you 20 bucks!"
She says, "I'm willing, let's go".
They get back to his place and after a bit of foreplay; they head for the bedroom. He loves the sex and can't get over how tight she is for such an old woman. He thinks that she's got to be a virgin.
After the wonderful performance, he rolls off of her and puffs, "Wow! Lady, if I had of known you were a virgin, I would have given you 50 bucks".
Surprised, she says, "If I had of known you were actually going to get a hard-on, I would have taken my pantyhose off!"