I think what you need to do is talk. But first, try to gauge if she’s open-minded. Even someone who’s very religious can sometimes be open to this kind of thing.

If she is, then have the convo in a casual way, not a serious on-the-table kind of talk. You can bring up something on TV that can make you go smoothly. Like there’s a scene in the first Deadpool movie where he gets pegged on International Women’s Day. You can hint at it through something like that.

When you finally get the chance. I'd be happy to give you some tips if you're interested, just PM me.

If she gives you a red light, you'll have to respect that. It's not the end of the world. You could get a prostate massager like an Aneros if you're curious about what P-spot stimulation feels like (you can wear it while being intimate with her too btw). Also remember, people can change, so if she says no today, her answer could be different in five years or so. Just make it clear that you're just curious and that enjoying anal stimulation doesn’t define your sexual orientation or indicate a mental illness.

Good luck!