Still recovering from that last one BD, but here's one along the same lines...
A man was at a bar one night, not really looking for a hook-up but certainly willing if something became available. It was almost time for last call and a fairly attractive lady who appeared to be in her early 40's approached him. He invited her to join him and they shared a couple drinks, then last call was given.
Well, apparently they hit it off well and the lady asked if he'd like to go home with her. He agreed, and on the way there, the lady asked if he'd be interested in a little mother-daughter action. Well he thought he hit the jackpot. He started thinking in his head what the approximate age of the daughter would be, he figured she'd be in her 20's. He told her that it sounded like fun, something he'd never done before but certainly looked forward to a fun threesome.
They arrived at her house, he got comfortable on the couch, and she said she'd go get her. She walked over to the staircase and yelled upstairs, "Mom, can you come on down?"