This essay explores the distributional impact that three forms of lumping have on single people without children: seat-assignment and seat-bargaining on public transportation, work-hour allocation, and single-family zoning. The first two involve lumps pursued by individuals outside of any legal regime; the last involves lumping by law. In all three, I submit, we tend to choose to devalue—or perhaps do not even perceive—the costs faced by the single person, and to assign relatively juiced-up value to the costs faced by those with families. The result in these arenas is that both society and law routinely externalize (hidden) costs onto single people and call the outcome both efficient and just when it might in fact be anything but.