I'd refuse to pitch in extra to cover him, share with him if he didn't contribute or invite him to the events I hosted.
When anyone said to me "Moocher doesn't have enough. We all need to kick in an extra $XX, I'd say in a very deadpan, emotionless voice "Sorry. I don't have extra." And I would not turn over one penny more than my share.
If he needed a ride in my car, I'd say very unamused "Sorry. Can't do it."
And I wouldn't JADE (Justify, Argue, Defend, Explain). Just "no."
And I would never invite him to my house again. Unfortunately, I have had to put my foot down like this. I have a fully functioning, normal member of society, cousin, in her 40s, who yells and screams at people and belittles them. She just has a bad temper. Her siblings and parents are used to it but I have stopped letting it go in the name of family harmony. I refused to invite her into my home for the family holiday gathering which is generally held at a different family member's house each year. That effectively means that I will no longer attend this function or see other cousins, but I refuse to be taken advantage of or abused in my own home and will not have her here.
Since you've already extended the invitation to Moocher, I agree with a PP. I think you should email all the rules to every guest
and end with "no exceptions." You could word it as:Because of XYZ circumstance, only those who are on the invitation list can be accommodated in my home. No uninvited guests. Any person, child or animal not on the original invitation list and the person who brings them will be turned away at the door. Thank you for your understanding.
I wouldn't discuss this with Moocher at all at the next gathering. I wouldn't call him or email him beyond this. I would just be prepared to greet guests at the door (versus being in the kitchen as they arrive and leaving the door unlocked so they can let themselves in) and I'd be prepared to say to any guest who broke these rules "I'm so sorry. I can't make an exception. It's not fair to the others because I've held them to the same standards. I cannot accommodate ABC infraction. I'm sure you understand." And if Moocher pitches at fit at the door, you smile sweetly, say "sorry" and close the door as you're saying it.