Tedious but exciting

The rest of lessons went uneventfull. At the end of the day I walked back to the shielded place in the cafeteria where I would meet the girls from this morning again. They were already waiting for me when I arrived.

"We thought you wouldn't come again." one of them said, "Of course, but I had another conversation with a teacher."

"Okay clear. We're here to exchange your stuff. I looked after your shoes and bra today. I've been careful with it, so I think there's a reward in it. My suggestion is that you get your bra back and I can keep those cool shoes. Or come up with another proposal." said the one who had been alluding to my shoes all morning.

"And I have to go home barefoot? No, I want my shoes back. Then you can get them tomorrow. Or you get my bra and matching panties?"

She looked at me with a strange look and said: "No I don't need worn underwear. But tomorrow is good if I can also keep your shoes that you are wearing then. The idea is that you walk around barefoot anyway. Or you give up your shoes now and it's done. It's up to you!"

I had to think about whether I had lost a pair of shoes (which were very expensive) or two pairs of shoes. But I lost the expensive one anyway. What was I supposed to do?