I don't generally share details, and don't ask for them - if a partner shares details that seem private, I'll usually ask if it's OK with their other partner to have that information shared with me. If any intimacy related details are being shared, it tends to be factual stuff about bdsm, and not sex. That said, I have no problem hearing or sharing details _most_ of the time if all parties are comfortable with that - there are certainly times I've wanted to share something but haven't because I haven't asked if it was OK. There are certainly times I've been nosy and wanted to know too, but it's not my place to be a voyeur if not asked, IMO. I will say I'd probably be more likely to share more details in some cases if I engaged in casual sex, but since my partners are all long term partners, I try hard not to overstep boundaries in that area. In your case if you want privacy and ask for it, that should be respected, and if you don't want to hear about things, that should be respected too.
Happiness will never come to those who fail to appreciate what they already have.