Christina Aguilera performed a heartfelt tribute to the late Whitney Houston [1] at the American Music Awards on Sunday night, and during her rendition of the classic "I Will Always Love You," the camera panned to fellow singer Pink [2], whose facial expression could be taken a handful of different ways. Was she impressed? Was she wincing? Was she perplexed? As Christina moved on to Whitney's "I Have Nothing," Pink was once again shown reacting in her front-row seat — this time, the "Beautiful Trauma" songstress could be seen smiling and applauding. Shade? You be the judge.

For what it's worth, the two singers had a well-known feud [3] during the early 2000s, during which they collaborated on a cover of "Lady Marmalade." Recently, Pink revealed that Christina actually "swung on" her at a club but that they've since patched things up. "She's so talented. And deep down — I've had bad days too — she's a really sweet person. I hadn't seen her in years and years and years. We became moms and we grew up and we hugged it out. It's that simple. I feel so good about that."