I hope u have asked hotels tht r starred 4 and above? De other local hotels mite look into de passports of the clients tht u wish 2 enroll into one room. Actually, none of dis was needed, all dey (De couple, as u hav stated) shud hav is come over and just placed a room request and paid 4 it using credit card. Flashin abt tht much, wud do de trick. Anywayz, other dan flashin der marriage certificate (Which dey dont hav) der is no other way 2 prove if dey r married, other dan... if der is de names of the personnels in der partner's passport. Gud luck..!!! But den again, dont worry, like i said... 4 star & above... nobody really bothers...!!!