Pittsburgh Pirates flamethrower Paul Skenes is mounting a serious challenge for the NL Cy Young award in his second MLB season while his girlfriend, Olivia Dunne, enjoys her time away from gymnastics.After calling time on her gymnastics career earlier this year, the former LSU Tigers star has been more active across social media platforms. Dunne, who shares a strong bond with her elder sister, Julz, often has playful interactions with her sibling on social media.In an Instagram post on Monday, Julz Dunne shared a picture of her in the backseat of a car. She also posed with Olivia in a picture from the post, which was captioned:"Backseat driver." View this post on Instagram Instagram PostOlivia Dunne took a playful jab at her sister in the comments:"If you are a backseat driver, what does that make me?"Julz fired back:"Passenger pain in the ahh."(Image source - Julz Dunne Instagram)While Julz and Olivia often engage in banter on Instagram, they support each other in their endeavors with the older Dunne hailing the former LSU gymnast as her "best friend.""That is my best friend, so, at the end of the day, that’s the relationship that really matters more than the ones from other people online that I don’t even know," Julz said in 2023.Paul Skenes' girlfriend Olivia Dunne receives heartfelt message from sister JulzJulz Dunne is her sister's biggest supporter as she was often seen cheering for Olivia Dunne during her time with the LSU Tigers.In an Instagram story on Monday, Julz shared a heartfelt message for her younger sister."Every morning you wake up, I'll be there... Every night at dinner, I'll be there.. Every birthday party, I'll be there. Every Christmas, I'll be there," Julz captioned her story featuring a picture of the Dunne sisters arriving at an event.(Image source - Julz Dunne Instagram)While Olivia Dunne made a name for herself for the LSU Tigers on the mat, Julz played softball at the high school level before attending LSU.