I remember an ex-GF which was quite religious. I thought it would be a problem, as I'm not religious. However, besides some boring (for me) visits to church, I'd say it didn't have much negative effect. Quite the opposite, in fact.
She would dress "sexy" when she got out with me. But when we were with her family and/or at church, she was more of a prude. Still, she found ways to play with me. For example, she used shirts that were buttoned up and were a bit tight for her boobs. Thus, it was normal for a button or two to pop open, thus allowing me (and everyone) to have a better view
But my favorite was a white summer dress she had. At first sight, it was boring: no cleavage, length was a bit below the knees. But the fabric was quite thin and if you mixed the appropriate light (i.e. bright sunlight) with some bright-colored panties (or thong), it could be quite an exciting show. She used to wear it with a red or yellow thong, thus you didn't even need much light to see it
Other than those details, she was just like any other girl and sex was very good, oral sex included.