For the last 16 years I have been my boss's dogsitter, unpaid (it started as a "favor" and has become a regular gig). She sometimes schedules me to have vacation days during weeks when she will be away and in need of a dogsitter. I have never objected because I still have enough vacation days to use for myself, but a friend thinks this scheduling practice (having me do unpaid favors/work on vacation time) is a violation of labor laws. Any thoughts? I should add that I do love the dogs and she has said "You don't have to do this if you don't want to," but it's awkward to refuse because I don't want to give the impression of not loving the dogs anymore.