Next time you go to their home , slide your finger across the top of their fridge which is most of the time last thing anybody will wipe the dust off , of. Then show that dirt laced finger to them.
You will surely loose them as your friends.
On a serious note. We being desi have something called murawwat , lihaz etc etc. English translation of these words would be being sensitive to other people’s feelings . If one is insensitive then we keep our cool and ignore idiotic behaviors and go on with our lives, if this idiotic behavior is not harming your in any way other than giving you some grief.