This probably stems from my childhood where I felt like my parents would have taken severe measures if I fucked up and "dishonored" them. A friend of mines parents allowed him to be locked in a room alone for 6 weeks with only a bible, bed and food at one of our home school programs facilities because he had been caught making out with a girl there so the fear of drastic measures akin to abandonment wasn't a stretch. While I know that I will be okay if I'm alone and I never want to control anyone, the fear of the pain of being abandoned is still there. Coming to the realization that sex isn't sacred to most people set off a subconscious alarm bell in my head "you can never feel safe". It's like boarding a plane with the belief that there are floatation devices under your seat but then mid flight the pilot comes on the PA "attention passengers, we are having engine trouble possibly forcing a water landing. Oh and by the way, the life vests under your seat - yeah that shit doesn't work."
Nothing is certain in life and while I still believe there can be love that lasts forever, I realized today that sex is not a life preserver and I have to just be prepared to swim if the ship goes down.