Sourpuss behavior refers to someone being consistently grumpy, negative, or unpleasant. Here are some examples:

1. Complaining about everything, even small inconveniences.
2. Always finding fault in others and their actions.
3. Refusing to participate in activities with a negative attitude.
4. Frequently criticizing or belittling others.
5. Reacting angrily to minor setbacks.
6. Being unresponsive or dismissive in conversations.
7. Often wearing a scowling or unfriendly expression.

Remember, it’s important to be understanding and compassionate when dealing with someone exhibiting sourpuss behavior, as there may be underlying reasons for their negativity.