Only hotel that is openly a 'swinger' type hotel that I know of is Copacabana in Jaco. The suites are nice but the normal rooms are fairly cramped. They do have a fenced clothing optional pool with beds around it which you won't find anywhere else that I know of. Have a couple that I take there about every 3 months and they just love it mainly because of the like-minded people they have met there. Here is the website...
http://www.copacabanadesirehotel.com/If you are thinking San Jose, any of the good hotels downtown like Sportsmen's, Amistad, or Zona2 (suites only) are very receptive to couples looking for some "extracurricular" activities but that will mainly involve a paid transaction with the girl of your choice. All three of those hotels have some fantastic rooms like the Amistad Penthouse or Sportsmen's Mansion Wing.
http://zona-2.com/http://www.sportsmenscr.com/http://www.hotelamistad.com/If you are thinking Guanacaste, know ATK just had a nice porn shoot at the Four Seasons
