Well, I am probably going against the grain here, but in my opinion you are a very bad friend indeed. Let us face it, if he had not referred you, you would have gotten nothing. Probably just looking greedily around for freebees...

If I were in your position and had won one flight, I'd have called him, depending on the mileage would have invited him for a drink or dinner. He would have been happy for you and all would be well.

You won a lot. The minimum would have been to have immediately offered him some flights or if you are really the greedy one, at least have said nothing.

It seems that elementary education and $$$ stop right at friendship. Too sad.

Let us wait for the future: you'll probably will enjoy your flights, I just wonder in what form the bill will be presented and then paid for.