Become a polygamist and increase your odds of your offspring contracting fumarase deficiency from the genetic defects that come with polygamy. There is a evolutionary reason for basic monogamy in some form and why nearly every culture practices it in some capacity.

But serious tho I can't see why someone would be dumb enough to want 5 wives.

That's FIVE women you have to financially care for, health insurance would be a complete bytch, you can never really connect with your kids in a deep, fundamental level nor provide for them financially to ensure they have a good life. Its not like having a classroom full of 20+ kids who you only have to worry about 40 hours a week only 8 months out of the year. Your life is those kids pretty much 24/7. All that for p*ssy? I love p*ssy and it feels amazing but NOT that amazing. Polygamy is for dummies and suckers hence why only fundie Mormons are obsessed with it.
Cheating isn't my cup of tea but if you seriously want a polygamist experience without the headache, just get a wife and a few mistresses on the side. Not only will you save a ton of money but you will still get the variety of women, you won't be financially tied to them and the other women are less likely to hog up a lot of your time.