Q: My best friend and I have been like sisters since we were 10 years old. We happen to both be house hunting in the same area at the same time — me with my husband, and she with her new-ish (but serious) live-in boyfriend. We stumbled across this super-cute duplex with mirror-image units. It wasn’t exactly what either couple was looking for, but the units would work well for both of our households, and we are each qualified for more than half of the price of the building. She and I trust each other implicitly, but the men in the group are wary of all four of us sharing a mortgage. What happens if someone fails to make their half of the mortgage payment?