Look up another spell

"Sorry, got carried away," you explain to Tina.

"That's alright," Tina says blushing looking at her new figure.

You quickly flip through the book while your friend is distracted, not being able to read any of the text you make out what you can from the diagrams.

Tina notices your malicious grin and in a panicked tone asks, "What are you doing, John?"

You read aloud another line from the book and poof! You are back in your apartment with Tina next to you, her breasts still as full as she was moments ago.