Do I care? I suppose it depends. If I'm going to be in a relationship with someone, it's kind of hard to be with them if they've been many people because I'm having to stack up with all the people they've been with, I'm no casanova, I'm just your average joe, not from a disney movie just someone decent at their sexual craft. I'm not someone who gets around a lot so I usually prefer someone around where I am experience-wise or even less so than me. But do I care what others do? No, have at it. If someone wants to have an open relationship or something like that, cool, I may even be open to that to an extent because long term relationships get old. But, if I ever have a fling, I want it to be with someone who doesn't do it a lot, like me, just a preference.
If the hypothetical idea of an afterlife means more to you than the objectively true reality we all share, then you deserve no respect.