@Vicoās vatican link in Post 64 is excellent. Be sure to read it for a greater understanding of the issues and your vulnerability, despite your staunch Catholic beliefs.
Fir starters: Your girlfriend is not actually your life partner, since the two of you havenāt committed to each other in marriage. In that case, Iād reassess my current relationship and lifetime goals.
Youāre dealing with your soulāyour ETERNAL soul! For this lifetime and all eternity! Why are you even considering the possibility of risking your faith under any circumstances, but especially with someone who successfully charges money in order to learn about his beliefs?!
This guyās in business, charging $75/hr because he can! Heās successful at drawing people in, or he wouldnāt be doing it. How are you going to successfully expose him? How are you going to instantly make intelligent comebacks? Whatās GirlFriend going to think when he hits you with something youāve never contemplated and youāre stunned into silence, even momentarily?
If you care about your girlfriend, how can you think of exposing yourself and her, even momentarily, to something that could endanger your soul and her soul?
What if your girlfriend doesnāt recognize the falsity? What, then? If sheās already hooked on these āout thereā ideas, learn how to teach her YOUR faith.
If others before you havenāt been able to stop this type of chicanery, what are the odds of your being successful? Please donāt jeopardize your soul. Run in the opposite direction.
If you do see this guy, in spite of all our admonitions, please be sure to read that Vatican link referenced by Vico.
Also, will you come back and tell us A) that you decided not to go, or B) what happened if you ended up going.
Best wishes. Iām praying for both of you, and even the charlatan.