Serena Williams husband buys FOUR billboards just to tell everyone that she’s an amazing mum

You don't need to be a tennis fan to know that Serena Williams is a cool chick.

Serena is so dope that she even made it on the cover of Vogue. 

And now her husband, Reddit co-founder Alexis Ohanian has shown off his love for his wife as he purchased four billboards in Palm Springs that show off that she's a GMOAT (Greatest Mother Of All Time.)