Yes, relationships are supposed to be give an take. There are people who are "givers" and those that are "takers." Most people have more one than the other, and the key is to be balanced. But, some people are an extreme of either, and when someone who is more of a giver ends up in a relationship with more of a taker, then that's when the problem happens.

People who are the extreme of takers I think are toxic. Because it never occures to them to give back.