Luke Thompson, Yerin Ha Interview on Stair Sex Scene

Luke Thompson and Yerin Ha weren’t exactly in lockstep when filming that climactic staircase scene.

The Bridgerton stars—who play Benedict Bridgerton and Sophie Baek, respectively, on season four—served up a surprising behind-the-scenes secret about how they prepared for their big sex scene in part one, out on Netflix Jan. 29.

“What we actually did is we both got ill,” Thompson exclusively told E! News’ Will Marfuggi in their joint interview. “But different scenes. We kept falling ill!”

Indeed, Ha quipped that both of them being sick “tells us we were very mentally a little bit weak, a little bit nervous, my immune system was down” for the steamy moment.

“But no, in all seriousness,” the 27-year-old continued, “I do think that with those scenes, it is just an extension of an emotion, and it’s there because it has to be, not because we’re just doing a steamy scene for a steamy scene’s sake.”