Well you obviously know that Gambit talks in the the third person. Most of his speech when talkin' to da fems is laced with with english and french cajun. Drop your g's. The is da. women are fems, men are hommes
cher
cherie
Feel free to look up other french/cajun endearments and swears. Babel fish is good for translating whole blocks of text if you want to him to ramble on ticked off in French. Remy is of course a very intelligent and sauve man he will try and charm his way out of anything so everything he says he means and has thought out. Don't forget to italicize anything french.
Have you tried googling things like 'cajun dialect' and 'writing cajun' yet? It might sound obvious, but a quick search reveals there's lots of info on words, expressions, phonetic spellings, etc., out there, if you're willing to do a bit of research.
I was stationed in Louisiana for a while...
Talking like a cajun is along the lines of having a mouthful of marbles. As long as NO ONE has any fucking clue what you're saying, you're on the right track.