always be cautious of those that say they fall in love when they've never known you in person. Yes there is a big difference. It is likely he never respected you in the first place and what I mean by that is this. There are those that strike up conversation, feigning friendship for one ulterior motive...to get in your pants. Sure he'll be the ear to your words because he has a goal.
A friend who knows you are married can love you as a friend if they actually love you, otherwise he has no respect for you, your marriage, your husband and especially your kids.
Let this person who is of lesser psychological fortitude go to the winds. Something isn't right there.
PS, I've been avoiding those that kill too...this sounds like the type...but that's just me saying