Even MLK was a huge womanizer. This is definitely known.
There's been some other shit that's come out about him though, but it's one of those things where you sort of have to make your own judgment call that he was just fucking around on his wife all the time or he was approaching freak level with the sex shit.
Nowhere near Diddy level of course, but there's a bit going on that he knew about some rape shit that his fellows were involved with and not only did he not try to stop it, he was egging them on.
Is it true or is it just the FBI making up shit? Well again that's what you gotta decide, along with if something like this cancels out all the other stuff he did.