Well actually this would be more like me seeing you coming, going "They look gay." Then instead of being friendly toward you when you speak to me, I simply make an off color comment to make you uncomfortable and bewildered. Then I get a good chuckle with my friend on the bus, then come online to brag about the situation so that others can laugh with me in support.
And yet very few people will open up with such a line as the OP mentioned, other than heavily religious people, typically of a Christian faith. As to date, I actually haven't met anyone who's opened with that line and wasn't
trying to peddle their religion. Following up with trying to steer the conversation back to the afterlife of choice makes it even more so. Just how long would you prefer she had waited, until he was just getting into his speech? Or would have perhaps been too early, as he may have been just sharing a moment of inspiration surrounding his faith? Later on when he had already picked up steam? What exactly is your personal criteria for one to know a person's stance on such things?
And as for making light of it, I quite frankly don't blame her. I can't even sit on campus to enjoy a snack, some music and a book between classes without some random person trying to walk over and hand me a collection of New Testament and Proverbs. (Amusingly might I add, while I was reading "The Atheist's Handbook") At that point, you either mutter off the thousandth incantation of 'no, thank you' and probably risk your ever growing irritation showing, or attempt to make light of it. I for one, unless they are unduly aggressive about it, (as has happened more than once to me) am more apt to either ignore them utterly, or try to make light of it somehow.
My humor of choice is asking the uncomfortable questions (no, not raunchy ones
) until they skirt around me from then on.