Do you, have child custody determined?
As an aside, what if he then, maybe, starts to use your son... as a way to get dates and have relationships.
Meaning, what if, he one day wants to have, physical custody of your son, as a way to get women? Who may also have children?
Who knows.
There are different types of child custody. And I would really, research this.
Here is a link on it:
http://www.nolo.com/legal-encyclopedia/types-of-child-cus...
http://divorcesupport.about.com/od/maritalproblems/p/chil...
http://singleparents.about.com/od/legalissues/a/typesofcu...
The thing is, he IS using your son's photo, to troll for women.
Then he will inevitably hook up with them. And, if one day, the woman says "oh can I meet your son?" or, "We should get our kids together..." then what??? He may then, try and get your son, and custody of him.
And/if... one day he re-marries or has a Fiance.
Ya never know.
Think ahead.
Be wise.
Get your ducks in a row.
And do it now.
Get custody, pinned down for your and your son's benefit.
Think ahead.