It's a good thing Jake Gyllenhaal steered clear of Las Vegas this weekend.
Fortunately, the "Mean" singer, 21, and just-wed Witherspoon, 35, showed no signs of hostility at the star-studded event, where they happily posed for photos together during the show.
Swift -- who won the Entertainer of the Year award -- even chatted with UsMagazine.com about her big win.
"This is absolutely mind-blowing to me," Swift (in Elie Saab) told Us. "It's from the fans, and that means the world."