Brits host Jack Whitehall's quip about fathers grabbing "scatter cushions" following Little Mix's performance was the most complained about moment of the show.
The music awards ceremony has sparked disapproval over the years because of swearing and scantily-clad singers.
But comedian Whitehall's joke about fathers provoked the most complaints from this year's ITV show, Ofcom told the Press Association.
Girl group Little Mix took to the stage in bra tops, thigh boots and corsets to sing Woman Like Me with South London rapper Ms Banks.
"Raunchy - dads up and down the country awkwardly fumbling for a scatter cushion right now," Whitehall said.
Broadcasting watchdog Ofcom said it received 38 complaints about the music awards ceremony.
Whitehall's joke after the Little Mix performance was the main issue, prompting 25 complaints.
Most of the others objected to the sexual tone of the group's dance routine.
'We will assess these complaints'
Girl group Little Mix during their performance of 'Woman Like Me' at the 2019 Brits awards.
An Ofcom spokeswoman said: "We will assess these complaints before deciding whether or not to investigate."
Whitehall peppered the awards show with several jokes, including one about Naomi Campbell's "current squeeze" Liam Payne.
He said: "His surname is Payne, which is what he'll be in a world of if he crosses her."
Introducing best British group, he said: "This year was all about reunions. First the Spice Girls, then Bros, and finally Westlife announced that they were back in the studio.
"Suddenly a hard border with Ireland doesn't sound quite as bad."
Before Little Mix's performance he told viewers: "Girl bands tend to crash and burn quicker than Prince Philip on a country drive but our next performers have bucked the trend."
He added: "Their old boss Simon Cowell will be asking his surgeon to put a brave face on him if they win big tonight."