Girlfriend angry for peeing in the sea, is it a normal thing to do?

Currently on holiday in Corfu for our 2 year anniversary, I went into the sea to take a piss while my GF was at the bar, when she came back I told her I went for a wee in the sea and she said she was disgusted and that her parents would be disgusted, but my family have been peeing in the sea for years I do see what’s wrong with it? Is it a normal thing to do?