Thinking I should block

I added one of my brothers friends on Facebook a few days ago

We know each other from our high school days

He has been trying to flirt with me and tonight he said just an FYI I work with someone who knows your husband and he’s told me he’s a POS and if there’s anything I want from your husband it’s….you

I asked how did that come up as discussion?

He refused to say

So now I’m like ok I didn’t cheat but I don’t like the fact that this is happening. I don’t talk to this guy and have ignored all advances. Maybe I need to relax and it’s nothing. Idk what he has up his sleeve 😒

I’m scared to block in case of retaliation sooooo