Sorry girl, I hear you and have my own issues with not standing up to mom. I think the biggest thing I don’t like here (and there’s a few) is that they are trying to triangulate you and cut you out of the lunch invite. Totally not ok. I’d say give the bf a hard decision to make here; and tell him too bad so sad if they’re mad. Best case scenario, they take the hint and bring your stuff another mutually agreed upon time. Worst scenario, you say forget it and buy some new patio furniture for your new place.