They got a lot of funny looks from their friends.

Once upon a time, within the suburban landscape where Greg Heffley and his older brother Rodrick lived, arrived an eccentric character named Fregley. He was a strange neighborhood kid, the sort of friend Greg's mother would insist him on making friends with. On one uncommonly peculiar weekend, Fregley was invited over for a sleepover at Greg's place, a gathering that Greg with all power tried to avoid, but alas, his mother convinced him otherwise. Greg's older brother, Rodrick, a notorious prankster, had no idea what was to come. After an evening of video games, comic books, and a whole load of popcorn, everyone eventually drifted to a deep sleep except for mischievous Fregley. An idea flickered in his mind. He decided to pull a prank on Rodrick, something unprecedented and imaginably hilarious in its own way. With stealth of a cat, Fregley sneaked into Rodrick's room and swapped their underwear. The thought of wearing Rodrick's underwear excited Fregley immensely, as if he was going to acquire some sort of superpowers or at least become a bit cooler. Morning dawned, and in the usual chaos of the Heffley household, both Rodrick and Fregley, in a hurry, didn't notice the switch. Fregley slipped on Rodrick's rebellious-looking black undies, grinning from ear to ear, while Rodrick found himself puzzled by the rather nerdy underpants he stumbled upon. In the flurry of getting ready and catching the bus on time, they both decided to carry on. The day at school was a rollicking rollercoaster ride. Rodrick, always known for his devil-may-care attitude, felt surprisingly conscious about the unusual under garment, and even a bit nerdy, while Fregley found himself strutting down school hallways as if he was the rocker himself, thanks to Rodrick's "cooler" undies. Word of this incident spread like wildfire when Fregley, in all his excitement, spilled the beans at lunch, making Rodrick the laughing stock and Fregley the unexpected hero of the day. Everyone chuckled at how the tables had turned for a day, all thanks to a prank by Fregley, forever remembered as the great underwear switch. To their relief, no more such pranks followed in the future sleepovers at the Heffley's, but the incident served as a reminder to Rodrick - that he too could fall prey to an amusing prank, and for Fregley, it was his moment in the sun, where he undeniably had the last laugh.