The story as I see it is as follows:
Roger, still reeling from Friday night, was wandering around in a drunken stupor on the bus. In order to get the maximum enjoyment from the sideshow that was Roger, somebody dared him to put girls clothes on. Cas, always one to help out a friend in need, just happened to have a spare skirt with her and she pulled it out of her bag. Roger, oblivious from the alcohol, was more than happy to put on this skirt. Then the real fun began. Roger decided that since he was wearing a skirt he should play the part and start chatting up all the boys on the bus. Having already struck out (comment removed by cian)
I'm sure it couldn't be further from the true story, which I also don't know, but towel it just shows how much fun your imagination can be.
As an aside, can anybody explain what is happening to my posts? They used to be so functional and factual but now they're just ramblings. Ramblings from my crazed mind at that. And senseless ramblings.