Over the course of five seasons (the sixth and final premieres on HBO in a matter of days) on HBO, Lena Dunham’s millennial comedy Girls has explored sex in just about every hot, awkward and just plain uncomfortable way it could, from Elijah trying women for once to that time Marnie just straight-up got a rimjob. Since the show is on the original home of prestige cable, creator Lena Dunham and company have largely had the freedom to go wherever they wanted with sex scenes, but it turns out there are some places even HBO can’t follow.

In a new oral (no pun intended, in this case) history of the show with The Hollywood Reporter ahead of the Season 6 premiere, Dunham, executive producer Judd Apatow, and former HBO entertainment president Sue Naegle recall the moment network executives finally flinched.

APATOW: From the beginning, we were aware that what we were doing was sexually provocative, and that’s what made it interesting and new and fun. Lena wanted to reveal something that is normally hidden—so often you’re not talking about a giant part of most people’s lives because people don’t want to portray it on film—and that opened up tons of stories that you’re usually not able to tell. But then we had a scene with a conclusion shot…

DUNHAM: It was actually cum arcing through a shot.

APATOW: And HBO said, “If this is in the show, we could lose our license.” We were like, “Oh my God, we’ve actually found the line at HBO.”

NAEGLE: In HBO’s defense, it was like a fire hose!

So the shot was cut, and Girls finally found its limit. I bet if the Game of Thrones team fought hard enough, though, they coud get something that graphic on air. You know, if they save it for the series finale and use the dragons.

Girls returns February 12.