I went through our photos of our last visit in 2017 and my wife was wearing flip flops at Rossini's. Guess we are no longer welcome at Rossini's anymore because it might disrespect the feelings of other guests #sensitive .

Rules are the rules though, that's the hotel's discretion and we're cool with that. It's unlikely we will be returning to the SGS in the foreseeable future anyway; it wasn't our favourite SPG property to start with (we love the St Regis despite its sometimes erratic service), the SGS's decor and ambience made us "feel old" every time we stayed there, once in a while we couldn't get a pool chair, plus I no longer hold Platinum status anyway; which means SPG Bangkok hotels might not see us for a bit whilst we try out other hotels.