Which is why I do this occasionally but on separate airlines, preferably mileage-earning partners.

You might even explore one way ticketing options. Perhaps to DC on Monday, then a round-trip ticket departing DC Wednesday, returning Monday, and another one way departing again Wednesday. Or if you're going to do this repeatedly, just buy a single one way ticket to your destination and book a bunch of round trips starting from DC. Often a round-trip is cheaper depending which side you start from. Need to look at every option.