“Would you mind being my guinea pig?”
You're studying massage therapy. You're not professional at it yet, but you need to practice. You're talking with your roommate about your training, and you want to ask her to let you practice on her. You say this.
Would you mind being my guinea pig?
"Would you mind ___ing?" is a polite way to ask someone to do something.
Use it when you expect the listener to say "yes" to your request. You can use "Would you mind" in lots of different situations: with friends, at work, etc.
Here are several examples of "Would you mind...":
A "guinea pig" is a kind of small, furry animal. At one time, scientists used guinea pigs for laboratory experiments. Today, we use the term "guinea pig" for a person who gets used to test something, like a new drug, product, or process:
He's been developing a new weightlifting routine and using me as a guinea pig. The results have actually been amazing.
Once in college I signed up to be a guinea pig for this medical test. They paid me a couple thousand dollars to take this drug that was supposed to help me quit smoking.
A person can "be" a guinea pig, or you can "use" someone else as a guinea pig.