This seems consistent with what I learned in CCD and Catholic school in the 90s-00s. We were always told that sexual pleasure was increased in a marriage and a sign of god blessing the marriage, whereas sexual pleasure outside of a marriage was cheap and damaging.
Edit: side note, I didn’t think this fucked me up until I got married and realized I’d felt ashamed every other time I’d had sex. I never believed in god, and this is pretty obviously trying to steer behavior, so I thought I was unaffected, but it’s still a brain virus
It’s pretty common, but I’ve always been very sex positive, with zero shame about nudity or bodily functions. I don’t notice any shame since I got married ¯\_(ツ)_/¯
Of course, I didn’t think there was any beforehand, so who knows