Cheating lovers need ways to purchase gifts for their lovers. The receipts and deliveries need to come somewhere. Some may choose to have things sent to work, but others will just get a PO box and have their things sent there. Keep in mind that going to a PO box is actually an inconvenience vs. bringing things straight to your home. If your lover suddenly has a PO box and you aren’t allowed to use it there might be something fishy going on.