The way to bust LMR it is to act like you don't care (or to actually not care, but you can't force that). I generally make a joke about them bringing it up in the first place:

(going back to my place)

Her: "I'm not this kind of girl!"

Me: "Wait..."

stops

Me: "You're not trying to have sex with me, are you?"

Or a make some joke about how we're going back to do a bible study.

And really that's the whole battle. If she's still keeping up the act when you get back, you just act like it doesn't phase you and keep doing whatever you were doing beforehand. So if you were making out and she stops you when you get to the finger dance, just keep making out and building up the pressure. She wants to do something, but is trying to make sure: 1) you aren't a piece of shit who is going to throw a fit if he doesn't get sex; and 2) she won't look like a slut.

I usually have them asking for it by the end of it.

(admitting she wants it)

Her: "Do you have a condom?"

Me: "You use those things?"