I wouldn't ask them that question because I have class.
Be careful about making sweeping statements like that. It's not classy
where you come from but that doesn't mean class is universal. Did you kiss the hands of all the Polish women you met? Why not, don't you have class?
But why do Poles do this? Its rude
again, rude for you, not them. Poles seem to respect directness; give a straight answer to a straight question and you're a man. Dodge, avoid, deceive and you're a coward or worse, a politician.
and quite honestly, whenever they ask me, I always sense some jealousy.
Possibly jealousy, possibly just curiosity. Possibly even pride, if it's you're family. Once you've left, they'll sit around the table and say "Oh, that Sebastian, living in another coutnry and making all that money. And he's one of us! Imagine that! One of us, out there in the West, so rich!" Then they'll be able to tell their neighbours and make THEM jealous.
Odd as it sounds, my family in England do exactly this.