companionship-currency
Refers to one or more periods of "quality time" that you spend with someone as "substitute payment" when you are unable to reimburse him monetarily for loans/services that he gives you.
One should always try to pay back his debts as promised, of course, but id this is not possible, companionship-currency can indeed be a wonderful "alternative reimbursement". Just be careful that you don't "abuse the privilege" --- i.e., "continuously" presume that merely spending time with someone is always adequate recompense for any favor that you ask of the person.