We do not allow "guests" on our lease. Our rules are immediate family only which is defined as spouse and your children. On leases we were on in the past it was invariable that the "guests" always shot young bucks that the paying members had agreed to give a pass on to grow up. It is not fair to the paying members that follow the rules. Every place is different but we really like the immediate family only rule.
In the OP case I would not invite that guest back. If that person is a true friend they will understand they broke the rule and brought that upon themselves and not harbor any bad feelings.
