Re: WWYD... overweight friend and new furniture...
I'm not nearly as heavy as Bob. I'm pushing 300 though, and have been treacherous to most outdoor/camping type chairs for the last 100 or so pounds. I'm mortally embarrassed about breaking furniture, and have done so to handmade items that can't be replaced without a lot of labor. I opt for the floor or the ground often to avoid it. Please, be honest with Bob. Tell him you're concerned for the furniture and ask him to bring something of his own. A grown woman should have no problems finding a calm, polite-as-possible delivery of her concerns over his safety, as a breaking chair could injure him just as easily as the steps that are questionable.
Get some 2"x6"s and some plywood to make a temp ramp for everyone's safety, but include the 2x6s because if he's that big plywood may not be sturdy enough. Ask him to bring a chair. If he doesn't have a chair when he shows up, have something nicer for him to sit on, on the ground or floor, if you don't already have something sturdy enough for him on hand. A nicer rug or blanket, something that won't get damp from the ground when he sits but can be laundered. Plan it out so he won't be excluded from the conversations and stuff if he's sitting on the ground to be nice, but be honest and ask him to not use your chairs at all or to not try the rest if he breaks one.
, proud parents to Bob>
ISO my sanity.
Did I mention that I've misplaced my sanity?