Neighbors bet confusion

I was playing roulette with a couple neighbors the other night and things got weird about shared bets. Somebody put a few chips on red and my other neighbor kind of nudged his chip into the pile, claiming half the action once the win hit. Nothing was agreed before and it turned into a whole argument over who gets what. I just kept my own chips separate to avoid the drama, but now they want “group” bets next time.

Does anyone here actually do group bets at the table with friends, or is that just a bad idea? How do you keep it fair and avoid these messy scenes, especially if things get heated?