Ugh, sometimes it's just TOO MUCH to try to coordinate with Mom and her overbearing partner that she just started seeing but insists on coming to every family function, and your Dad and his lady friend (are they together? Are they broken up? He keeps complaining about her but won't leave her) SO LET'S MAKE IT SIMPLE AND IGNORE THEM BOTH. (Also, PS - thank god I have a sibling like you!)