“Snape, headmaster! Snape in Dumbledore’s study — Merlin’s pants!” she shrieked, making both Harry and Ron jump. She leapt up from the table and hurtled from the room, shouting as she went, “I’ll be back in a minute!”
“‘Merlin’s pants’?” repeated Ron, looking amused. “She must be upset.” He pulled the newspaper toward him and perused the article about Snape.
…
“Oh, here she is,” Ron added, craning around in his seat to watch Hermione reentering the kitchen. “And what in the name of Merlin’s most baggy Y Fronts was that about?”

Harry Potter and the Deathly Hallows – J.K. Rowling