The former Disney star flashed a serious amount of flesh in a cleavage-busting top as she walked the red carpet.
The LDB also exposed the singer's toned tummy with a cut-out section.
Selena finished off her smoking look with her hair worn in a loose side plait and a slick of plum lipstick.
She was the star guest at the party held in celebration of the November issue, after appearing lingerie-clad on its cover.
She used the interview inside to hit back at New Zealand singer Lorde, who recently claimed that her song 'Come And Get It' is anti-feminist.
She said: "That’s not feminism. [Lorde is] not supporting other women. That’s my honest opinion, that’s what I would say to her if I saw her."
"I actually covered her song in all of my shows that I’ve done so far. I’m not sure if I’m going to continue that," she added.