Finding an all-inclusive resort with an adult-only policy doesn't take a lot of research time or chops. Finding one with a couples-only policy, however, is a bigger challenge—but not one that you'll have to face because Oyster has done the work for you. These all-inclusives take their adult-only vibes to the next level by admitting only couples. This policy translates to an environment free of not only families with small children, but also friend groups, single people, and business travelers, so that the hotel can truly cater exclusively to couples. (Some will occasionally make exceptions, like in the case of an on-site wedding with a few solo guests.) From the Barbados outpost of a well-oiled resort machine to a kinky Riviera Maya resort for swingers and voyeurs, these couples-only all-inclusives are tailor-made for romantic twosomes.