Photographs of the seating arrangements at the music awards turned up on the Internet showing placards with the couple's names next to one another, TMZ reported Saturday.
Celebrities can request to sit apart from one another at events like the Billboard awards, which will be held Sunday, TMZ said.
Bieber and Gomez split in November after a two-year romance and have been on-again, off-again since.
Kate Middleton recycles dress at movie premiere
Couple mistakenly served bag of cash at McDonald's drive-thru