Welll, it depends. Apparently semen can live a terrifyingly long time in the right environment. It could sneak in. Sometimes.
God, I'm scarred for life. Thanks wine and crime lol
It probably depends on your instance, but if I go to everything and sort by active, there are a bunch of posts at the top with hundreds of comments. On Lemmy it's way more normal to comment on a post that's a couple days old than it has been on Reddit for almost a decade.