TMZ has learned Spencer Pratt and Heidi Montag are at the same hotel in Costa Rica ... where Spencer is giving his estranged wife a very clear ultimatum: "Either do another reality show with me or I'm going to release amazing sexual content."
Spencer tells TMZ that he has an "entire website's" worth of footage, saying, "I will knock Club Jenna out of the water."
Pratt says they have been saying in separate hotel rooms and they have been having ongoing, semi-hysterical discussions -- in which Spencer has demanded that Heidi tear up the divorce papers and do a revealing reality show on why she needs to get away from him.
As Spencer puts it, "You cannot turn off the Speidi machine."
Spencer is very clear ... he will release a flurry of sex tapes if she does not agree. Spencer added, "I am a wild sexual freak and I love sex."...
Spencer went on to say he thinks releasing the tapes will be good for Heidi, saying, "When I realized how much Kim [Kardashian] was making, my logic is this is the best thing I can do for my ex-wife. Kim is on the cover of Allure right now. Heidi isnít on the cover of Allure."
(Vivid President Stephen) Hirsch says if the sex tape is going to be the biggest selling sex tape ever -- and raise Heidi's profile to Kim Kardashian levels...