I intend to give money to a friend from UK who will be using the funds to play poker. Poker winnings are not taxed in the UK. I will assume entire risk if he loses the investment. If he makes a profit, he will keep 20% of the winnings and give me 80%. I on the other hand have to pay taxes for this foreign income. What category does this fall under? Does it fall under gambling winnings (though I'm not the one gambling)? Or is it returns from a partnership between him and I (as an investment and getting profit distributions)

Thanks in advance