Jealousy

What's gotten into my husband lately?
I added a friend on facebook who happens to be male (and pretty darn old) and my husband is getting jealous.  This guy and I were friends a long time ago and have been friends since I was about 18.  We don't talk very often anymore, but that's okay.  We keep in touch every once in a while.  This guy is kind of like family.
Anyway, my husband is jealous of this guy and has absolutely no reason to be.
One, I've never physically met this guy.  We used to talk online and on the phone.  So what if we happened to meet on a dating site?  He is married.  I don't go for married men.
Two, this guy is really old.  He has enough health issues to make me worry.  I wouldn't go for a guy who is constantly going to the hospital.  No offense to anyone.  I don't go for military guys either.
And three.  He lives in a different state.

I don't know why he is suddenly jealous of a guy I rarely ever talk to.  It's weird.  I knew he had insecurity issues, but this is weird even for him.

Po1s0n.