I am assuming each couple is in a different household. According to the FAQ on insuremytrip, most carriers prefer everyone being in the same household, however, there are some carriers that will sell a group policy to people in different households. The only exception is if they live in different states, then they will need to be on separate policies due to different laws between the states. Information here https://www.insuremytrip.com/insuring-your-trip/different-households-or-states/