Feeling resentful

Every weekend I meet a group of friends and we exercise together and then go to a cafe to hang out. One of these friends never buys himself a drink or snack. Instead he will ask someone else to buy him one…often me. Perhaps because he ‘doesn’t have any money on him’ or today it was because he didn’t bring a mask to wear to go into the cafe.
If he was hard up, it would be my pleasure to get him a drink. But he almost certainly earns at least 2x what I earn. My other friends almost fall over themselves to give him something.
Usually one buys him a snack and then it seems to fall onto me to get him a drink. To make matters worse he doesn’t even say thank you when you do get him one. Its like its expected.

I don’t know where all this stems from, but I am feeling resentful. He never offers to buy us anything on the rare days he does bring his wallet and buys himself something
I don’t like feeling resentful, so I either have to be ok with buying him a drink every week or be ok and say no I am not getting him anything.

C Friend asks me to get him a drink
Thought why can’t he buy his own, he earns more than me.
Feeling …Resentful
Action Buy him a drink
Result Me thinking about the situation +++

Could you help me develop a positive model…I am completely blocked.