Bachelor in Paradise viewers have reacted angrily after a teased "lesbian kiss", used in pre-season promos to amp up excitement for the Ten series, turned out to be a lie.

Viewers of Tuesday night's episode took to social media to accuse Ten of "queerbaiting", and using a contestant’s sexuality to sensationally attract viewers.

The show's pre-season promo, unveiled by Ten last month, had hinted at a same-sex hook-up, with the openly bisexual Megan Marx shown kissing another mysterious, longhaired contestant during a late night swim.

"She's absolutely gorgeous, she's definitely my type of girl," the promo shows Marx saying, over images of castmate Elora Murger.

But Tuesday night's episode confirmed that the longhaired cast member was in fact a man: Thomas Perras, a contestant from Canada's The Bachelorette, who was brought back into the series after being dumped on Monday, just a day into his Paradise adventure.