Answer:
"so there's this lesbian girl and a straight girl and they are going shopping together and they get in the car and the lesbian says 'the stoplight three blocks away will be red when we get there.' sure enough, it is. the straight girl says 'how did you know that?' and the lesbian says 'lesbians know everything.'
"so they get to the mall and then the lesbian says 'the third parking spot in the fourth row in front of sears on the other side of the mall is open' and they drive over there and sure enough it is open. the straight girl says 'how did you know that?' the lesbian says: 'lesbians know everything.'
"so they walk into the mall and then they get to that...uh...you know, the moving stairs that you ride on in the mall...uh...the..."
(other person helps you out and says escalator)
"oh, yeah. lesbians know everything"
ha ha ha