Contrary to popular belief, most billionaires stay married to their first wives, according to Forbes. And even the ones who get divorced rarely marry much-younger women:

…the serially divorcing billionaire is a unicorn, a myth. Most filthy rich men are fairly monogamous. Fewer than 100 people on the Forbes 400 list of richest Americans have been married more than once. Fewer than 20 are on a third wife. The elite four-wife club, which offers your best chance at seeing an old guy marry a woman 30 years his junior, has a mere 6 members. The reality is that billionaires who divorce often tend to remarry women closer to their age, with a few dramatic exceptions.