Serena Williams Poses in Swimsuit – With “Massive Butt”

 Harper's Bazaar

In the August issue of Harper's Bazaar, Serena Williams sports a swimsuit by Eres.

The tennis champ, 28, says she was 23 when she realized she wasn't like her leggy sister Venus.

"She's totally different. I'm super curvy," says Serena, who split from beau Common in April. "I have big boobs and this massive butt. She's tall and she's like a model and she fits everything."

Growing up, she says she always found herself "wanting to be" her sister, "wanting to look like her, and I was always fitting in her clothes, but then one day I couldn't. But it's fine. Now I'm obviously good, but it's a weird thing.

"Since I don't look like every other girl, it takes a while to be okay with that. To be different. But different is good," she continues.

Her favorite part of her body? "My smile," she says. "Does that count? I think a smile can make your whole body. Models, they look fabulous, but they don't smile and they look so mad. But I like my smile, how it's bright and it's nice. Good thing my braces worked out."

If she could change one thing about her body, she'd alter her arms. "People want more fit arms, but my arms are too fit," she says. "But I'm not complaining. They pay my bills."

She says she does Pilates (two or three times a week) and yoga to lean out her body "so I won’t be bulky."

When she's training for a tournament, she'll tack on "a couple of hours of hitting, then an hour or two of cardio and strengthening in the gym." (If she's at her home in L.A., she'll run the half mile up a hill to Venus' house instead of driving.)

One thing she won't do: Diet.

"I don't even know the D word," she says. Instead, she'll stick to "smaller portions of every meal, a lot of grilled or baked chicken or fish, and steamed veggies."

Still, she admits, "I can never turn down a good piece of cherry pie, but all I know is that in 10 years, I don't want to be as wide as this couch."

Sign up now for the Us Weekly newsletter to get breaking celebrity news, hot pics and more delivered straight to your inbox!

Want stories like these delivered straight to your phone? Download the Us Weekly iPhone app now!