Ends badly because their wives demand it or ends badly simply because they move out from their family home?
Most people would say living with the husband’s parents is more likely to cause problems than moving away from them (but still obviously better to stay close by).
As for bad habits and ugly personality I don’t think u can get much worse than people who think it’s ok to ‘mess around’ before marriage with multiple partners but then demand or expect their other halves to be virgins..