Stranger from Facebook?

[Your helper]

so i posted a picture of myself (just a normal selfie) and he liked it and commented i think. Then he messaged me the next or same day and said "merry christmas beauty"! Even though I didn't know him, I was still polite and said merry Christmas back. Then he said "hi lovely" then he asked me if I speak french and I said yes. So he called me pretty in french i said thanks! Then I said "i don't mean to sound rude, but have i ever met you or do i have really bad memory haha" then he said that if i wanted him to leave me alone , he would. I said "no its ok thats not what i meant".
I asked him how old he was and he said he is 14 and so am ! (but he told me his age before I told him mine). Then he had to go and he called me pretty again lol.

We have 4 mutual friends by the way, I don't plan on ever meeting him or anything.
I don't know what to do, what should I ask him? A selfie to know if he's real but thats creeppyy

I want to block him because what if hes a fake, BUT we have mutual friends help

BTW, he's the first guy that ever called me pretty