Reciprocity means both people occasionally carry more without treating kindness like debt.

There will be seasons when one of you gives far more, and treating that as a debt is what ruins it. Help offered with a mental invoice attached is not really help, and the person receiving it can always feel the invoice. What makes the imbalance workable is that both people expect the direction to reverse eventually and neither is counting in the meantime.

When you give a lot to a friend in a hard year, decide at the outset that it is not a loan. And when you are the one receiving, accept it without excessive apology. The gracious version on both sides is what makes the next round possible.