You don't...

What could you possibly say?

And besides, Beth is back before you can think of anything. She's carrying a box of stuff, with a big grin on her face. Beth puts the box on the table and locks the door.

"Honey, drop your pants." Erica commands you, and you obey without resistance. You are naked from the waist when Beth turns back to the two of you.

"Jesus! That is one TINY worm!!", Beth exclaims as she lays eyes on your genitals, sending Erica into giggles.

"Yep! He's too small to satisfy! Think you can help?"

"You came to the right place!", Beth smirks and opens the box.