Paul Skenes will be throwing 100 MPH on the mound at the MLB All-Star Game in just a few hours ... but he's already bringing the heat to the event's red carpet -- with Livvy Dunne right by his side!!
The Pittsburgh Pirates ace -- who's slated to start the mid-summer classic for the National League later Tuesday -- arrived at Globe Life Field in an all-white suit with a black tie. His LSU star gymnast girlfriend, meanwhile, turned heads in a beige halter top dress.