1. No I'm not sensitive. It is after all, not my name, but just a handle, and yes it was a playful gesture.
2. You misunderstood what I said about diminutives applying to the referent by diminishing them socially. That's not the same as demeaning someone. Even an affectionate nickname reduces, minimises, the social distance between you and the one the diminutive is applied to. It puts them on the same level as you. Whether this is rude or not depends on the ACTUAL relationship between the people. If you were to go up to the President of the USA (assuming you are not known to him) and say "Hey Georgie baby!" it probably would be taken as inappropriate.

But let me make it quite clear - you may desecrate my handle in any way you wish and it won't upset me.