Gray Suede Shoes

Dear Law School Ethicist:

I am a law teacher. In my first year class I got into a discussion with a pretty good student. At some point he noted my shoes (Ecco Grey Suede with semi capped toe) and said he liked them. Later on in the conversation he suggested a  bet. If he booked my class, I would buy him a pair of shoes like the ones he was admiring. If he did not book it, he had to prepare an elegant dinner for me and my family. When I graded his exam it looked like he might book the course until I made a small adjustment in his grade. I lowered it 2 points because he should not gamble. I did not have to buy the shoes. Have I done the right thing? It was for his own good.

Shoebug