I'm rolling the dice at the craps table at the Mandalay for a long time and making money for everyone. My friend bets $5 of his own money on hard eight for me, the shooter. I hit hard eight and the bet wins a bunch of money for ME. My friend asks for his $5 back, so I gladly give it back out of courtesy, but we both knew that the winnings were all mine.
Your friend should have referred his wife or children or parents if he wanted to keep the miles in the family. Take him out to dinner and you're even.