A Republican congressman from Louisiana named Vance McAllister was caught by a security camera making out with a STAFFER . . . even though he's been MARRIED for 16 years.  The staffer was married too.



He's the one who brought Willie Robertson from "Duck Dynasty" to Obama's last State of the Union, during the controversy overPhil Robertson's comments about gay marriage.  And he campaigned as a conservative Christian.



The footage is from December.  And yesterday, McAllister released a statement saying, quote, "I'm asking for forgiveness from God, my wife, my kids, my staff, and my constituents."



(Search for "Vance McAllister Caught in Extramarital Encounter."  The kissing starts at :24. .)