MEMO TO BEN AFFLECK: Diamonds – not hawgs – are a girl’s best friend!

Ben, a hardcore motorcycle enthusiast, bought wife JENNIFER GARNER a Harley- Davidson Sportster two years ago, figuring athletic Wifey would love to share his passion.

But alas, reports My Biker Spy, the busy mom of three’s barely used the bike.

“It’s been gathering dust for two years, so Jennifer told Ben to get rid of it. Ben didn’t want to keep it for his collection because it’s made for smaller-statured riders, so he started asking pals if they wanted a bike with less than 200 miles on it – and one recalled that actress OLIVIA MUNN, who’s starring in CHANNING TATUM’s new flick ‘Magic Mike,’ had gotten her motorcycle license.

Olivia met with Ben, rode the bike, loved it, and he offered her a really good deal – $5,000, half what he’d paid for it.”

Did Olivia jump on the deal?

“She told Ben, ‘I have $4,500 cash – take it or leave it.’”

Ben took it – and Olivia zoomed off to high adventure!