You need to pass partner2 transaction auth inorder to execute the contract action data, not partner1's

{ "timestamp" :12345567, "author" : "partner2",....}

cleos multisig propose testfin '[{"actor": "partner2", "permission": "active"}]' '[{"actor": "partner2", "permission": "active"}]' mltisigmetup meetup '{ "timestamp" :12345567, "author" : "partner2", "male":"ash" , "female":"swap","ismet":"yes" }' -p partner1

aprove

cleos multisig approve testfin test2 '{"actor": "pat2", "permission": "active"}' -p partner2

exec

cleos multisig exec partner1 testfin -p partner1

check table

cleos get table mltisigmetup mltisigmetup posts

You need to pass partner2 transaction auth in contract action data inorder to execute , not partner1's

{ "timestamp" :12345567, "author" : "partner2",....}

cleos multisig propose testfin '[{"actor": "partner2", "permission": "active"}]' '[{"actor": "partner2", "permission": "active"}]' mltisigmetup meetup '{ "timestamp" :12345567, "author" : "partner2", "male":"ash" , "female":"swap","ismet":"yes" }' -p partner1

aprove

cleos multisig approve partner1 testfin '{"actor": "partner2", "permission": "active"}' -p partner2

exec

cleos multisig exec partner1 testfin -p partner1

check table

cleos get table mltisigmetup mltisigmetup posts