Modest is the hottest!

Reese Witherspoon covered up her huge belly tattoo with a one-piece swimsuit while vacationing in Hawaii on Monday. The actress, 35, was all smiles as she and son Deacon, 7, hit the waves boogie boarding.

The Oscar winner first showed off her ink -- a star flanked by two birds -- while vacationing in Hawaii in August. A source tells Us Weekly the recently added stars symbolized her "new life and love" with hubby Jim Toth, who she married in March.

So how does Witherspoon, who is also mom to 12-year-old Ava, stay in shape? She's an avid runner!

In September, the star was actually hit by a car while jogging in Santa Monica. She suffered a quarter-sized gash on her forehead, but fortunately only suffered minor injuries and made a full recovery.