This is one of the main reasons why I keep my writing life separate from my personal life - and even then I maintain firm boundaries between acquaintances, colleagues and 'friends.' It is not because I am unfriendly or a snob, it is because experience has taught me that many ppl are not who they appear to be when talking to you - they will just as soon turn around and talk behind your back -

What your colleague did is jealousy at your success - it happens and can be vicious -