i would add nice comments and like some of the pics - dont be sarky or anything - everyone will see it and you will come off looking worse.
but say stuff like 'oh i remember that , how funny!' or ' i loved that painting on the wall at the back', or 'what a fun night that was'- ' love that dress' - just random stuff ... maybe even a 'is that my arm/leg/hair at the edge there?'
but sound genuine, not loaded comments
it may be enough to make the point, if not have a word with you son perhaps