Just take the losses and move on. There's no need to stay on that feeling when you've lost the bet while watching the game.
While it is to be enjoyed when you watch games and you want to see them win because you'll also win your money. But there's no need for you to stay on that shoe.
Look to the next games, bet again if you want to and from there start your next expectation and tune again to the game.
Many of them are upset with their bets that do not match their expectations, they tend not to accept the defeat that occurs and they become rebellious and emotional, even though they should be able to accept the crushing defeat, if they really want revenge they can do it again in the next session, by placing a bigger bet so they can reverse the defeat that has occurred, but that's also if their bet wins, because if they lose again they might get even more emotional, because people who gamble tend to get emotional easily because their gambling does not match expectations. Indeed, watching without gambling will lack the sensation, but if they want to bet while watching I think they must be prepared with the loss of money that is bet on it, also if they bet with their favorite team but they find defeat then they will feel twice the disappointment, because with the money lost as well as the loss of their favorite team, no matter how strong their team is it does not guarantee that they will get a victory. If you really want to bet, you must be ready for the risks that will occur, do not be unable to accept the defeat that occurs, because many of them cannot accept the defeat and become upset, even though they can do it again to try their luck again because maybe in the next session they will find victory, but no one knows about it, so no one can predict it exactly, because this is also not separated from luck.
I myself prefer to just watch by enjoying the fun of the game that takes place, because I myself do not dare to take the risk that will occur with the loss of money that I have or I put, because people's thoughts are different so maybe there are those who choose to watch while gambling because they feel more tense or more exciting sensation by betting on the team that he thinks is good. But I myself don't do that because I just want to enjoy the match naturally, my favorite team wins I'm happy, and my favorit team loses, that's it, if you think about it deeply it won't change the situation, as well as those who bet on their favorite team if they lose they don't have to think about the bet even if they think about it hard it won't change the situation that has happened. Accepting defeat well is what must be done as you said. because if among them there really are emotions when losing because they cannot accept their defeat, maybe this will trigger a fight with a friend who has a different team as a bet, after all the possibility of a clash could happen.