In a clip that has since gone viral across social media, the 38-year-old entertainer appears to scowl as Christina performed Houston's great ballad, 'I Will Always Love You' to celebrate the 25th anniversary of The Bodyguard.
Twitter user Mark Sundstrom posted, '@Pink and @Xtina deaded their beef last year and have been FRIENDS since, respecting each other's amazing talent as grown women. Stop creating something out of nothing.'
Pink quickly retweeted his comments and wrote, 'Yes. THIS. Christina f***ng killed it tonight for one of our favorite singers ever.
'This about Whitney, and I am in awe of Christina's talent. Show the clip where I'm in tears, you negative Nancy's.'
Pink and Christina's notorious feud began nearly 15 years ago after some dispute on who would sing the high notes in their hit song Lady Marmalade, which also featured Lil Kim and Mya.
However, it was reported last year that the two had squashed their feud and decided to focus on supporting each other's talents.
If you haven't yet seen Pink's amazing AMA's frock that everyone's talking about, check it out here.