A plan is hatched

"Happy birthday, my sweet," Vastra bent down and lovingly kissed Jenny.

"Is it done?" the birthday girl asked.

"It is. And Clara doesn't suspect a thing."

"But Strax-"

"Don't worry, he played his part to perfection. Clara has no idea her clothes have been destroyed."

Jenny wriggled with excitement at the thought of their guest's clothes being reduced to ash.

"And how does she seem?"

"Very uncomfortable and embarrassed."

"Perfect. I hope you don't mind doing this-"

Vastra placed a finger on her wife's lips.

"Hush, now. It's your birthday. If you want Clara Oswald to be naked, Clara Oswald will be naked."

Their cute guest being sensitive about her nudity and wearing nothing at all? This was going to be the best birthday ever!