Justin bieber/Selena Gomez
Justin Bieber and Selena Gomez at the 2015 Met GalaTwitter/Instagram

Justin Bieber was couldn't stop ogling at ex-girlfriend Selena Gomez at Met Gala as she wowed everyone in her stunning white Vera Wang gown.

The "Baby" singer was floored by the Texas beauty and sources said that he couldn't stop talking about her throughout the night. The Hollywood Life reported that Beiber sung words of praise about his ex to everyone at the Gala.

"Justin couldn't take his eyes off Selena at the Met Ball," told the insider, adding that he thought she "looked like a princess".

The website further wrote that the "Confident" singer even tried to warm up to Selena's bestie Cara Delevigne and took selfies with her so that he can be in the good books of the "The Heart Wants What It Wants" singer.

Any girl would have fallen for all his praises, but Selena did not pay any attention to it. In fact, it seemed like she was trying to make Justin realise what he had lost; and according to Hollywood Life, he fell right into her trap.

"Justin played right into her aloofness, which made him want her even more. It was perfect because this is exactly what she wanted," the source told the website.

In his last attempt to grab her attention, the 21-year-old shouted out to a TMZ cameraman, "Yo, Selena looked gorgeous at the Met Ball," before driving off to the Met Gala after-party [Watch the video below].

But nothing in this world could encourage Selena to talk to her old flame as sources from US Weekly said that at the after-party, hosted by Rihanna at Up & Down, the "Slow Down" singer avoided talking to Biebs even though the latter "tried very hard" to spark a conversation with her.

PROOF? Justin Bieber -- Still Thirsty for a Sip of Selena (VIDEO)YouTube