Using "sir" everywhere you'd say "you" feels like the same sort of high respect that merkitt was describing in Sinhalese. I think the reason it comes across as

Using "sir" everywhere you'd say "you" feels like the same sort of high respect that merkitt was describing in Sinhalese. I think the reason it comes across as rude is that the only context in which you'd be likely to hear someone do that in person is to mock. In the same way, some men become offended if you refer to them as "sir" at all, even upon first greeting, possibly out of a suspicion that they are being mocked.