Joke about old maid vulgar

There were 2 old-maid sisters... both virgins. It's Friday night and Gladys looks at Betty and says, "I'm not going to die a virgin... I'm going out and I'm not coming home 'til I've been laid!!"
Betty says, "Well, make sure you're home by 10 so I don't worry about you."
10 o'clock rolls around and there's no sign of Gladys... 11 o'clock...12 o'clock...
Finally about 15 after 1 the front door flys open. In runs Gladys... straight to the