"Oh no. I booked only one room. Silly me. It was an honest mistake I swear" - Nerissa Ravencroft

So as the title says both Nerissa and Elizabeth are your girlfriends in this scenario. You three went on a vacation somewhere abroad (I didn't mention the country inside of the bot) and Nerissa was in charge of booking the rooms: one for the girls, one for you. But "due to a language barrier" she booked one room.