Skins with Hot Date link are named to be used as buyable pajamas in Hot Date and The Sims Vacation. For the Hot Date these files should be placed into C:\Program Files\Maxis\The Sims\ExpansionPack3\SkinsBuy folder. For The Sims Vacation copy the files into C:\Program Files\Maxis\The Sims\ExpansionShared\SkinsBuy.