In what situation does it usually happen несколько предложений

Milk leaks in situation when a dog plays with a pack and bites it too hard.

I usually smile when I hear a nice joke or see someone I like.

Snow usually falls in winter, especially at Christmas (it is called White Christmas then).

My granddad is monstrously angry in situations when he can't catch any fish at all however long he stays at the lake.

A man marries a girl when they love each other and their parents are not against their marriage.

I do my homework always, even if I am extremely sleepy or tired.