Give her a romper to wear

"I knew you were a whore, Jessica," Mallory started as Jessica fumed at that characterization, "but I'm not stupid and unprepared. Here," she fished out a romper from out of a duffel bag on the table, "this should keep you decent. I expect you to keep it on for the whole event, and give it back to me when you're done. If it's broke I'm charging you up to $200 for its repair or replacement."

"What, $200!" Jessica scoffed, "but it's so light and airy!"

"It's sure beating what you're wearing right now," Mallory handed it to Jessica, "besides, we're not leaving until you put it on."

With a sigh, Jessica got dressed in front of Mallory, somewhat self-conscious of how see-through the romper was. Satisfied, Mallory left the room with Jessica and guided her to the banquet.