Kate Middleton
Credit: Max Mumby/Indigo/Getty Images

After donning a string of stunning formal looks, Kate Middleton stepped out to celebrate Father's Day in a casually chic ensemble. The Duchess of Cambridge and little Prince George spent the day cheering on Prince William as he participated in a charity polo match at Cirencester Park Polo Club in England.

Middleton came out to support her husband on his first Father's Day dressed for the fun occasion in a ME+EM breton stripe top, medium wash jeans, and comfortable taupe Sebago boat shoes. The French-inspired cobalt blue and white striped shirt has quickly become one of Kate's favorite pieces, and features a scoop neckline, three-quarter-length sleeves, and ruched detailing to the bottom hem. For all you Middleton style fans out there, we have some great news—her go-to top is still available! You can grab the top ($72) now on the U.K. label's website