Tell her she can watch you change

"No it's ok. Guess you've seen pretty much all you're going to see anyway" you say as you begin to undo the second pair of jeans.

You can see that she's watching you carefully as you slip them off and get the third pair. She's pretty neat you think and clearly enjoying this.

The third jeans are a little tighter than the others. That gives you an idea. How far is she prepared to go?

"I'm not sure about the size of these ones, they seem a little tight and I'm not sure that I should fasten them up. What do you think? Do you want to give me a hand here?"