Condoms, Lube, and Finding the Perfect Sex Position: Out Director Matthew López Spills 'Red, White & Royal Blue' Secrets

Out playwright and film director Matthew López spilled some scalding tea on what went into the behind-the-scenes preparations for his debut feature, Prime Video's No. 1 streaming success "Red, White & Royal Blue," dishing about everything from Uma Thurman's Texas accent, to the changes he made when adapting Casey McQuiston's beloved novel to the screen, to bedding down with the movie's intimacy coordinator in order to work out how to show audiences what the movie's male leads were getting up to in a central sex scene.

Chatting with Variety, López revealed that no detail was too small to command his thoughtful attention, from the condom wrappers sharp-eyed viewers can spot to the level of lube in a bedside tube.

Another carefully considered element was the age of the two male protagonists, one of whom – Prince Henry (Nicholas Galitzine) – is a member of the British royal family and only two heartbeats away from the throne, while the other – Alex (Taylor Zakhar Perez) – is the son of U.S. President Ellen Claremont (Thurman), a Democrat and the country's first female POTUS.

"I really wanted there to be some genuine stakes and gravity for these characters," López said about making the film's lead characters older than their novelistic counterparts. "If they were too young, you could just explain this away as puppy love. I wanted this movie to be about that first real romance of your life, the first real love affair, the first real love."

In another change, López opted to let Prince Henry speak for himself and stand up for his equality as a gay man, rather than allowing his mother the queen to defend him. Departing from what was at the time of the movie's production the reality of a Queen of England, López also depicted the British monarch as a king – namely, Henry's grandfather, played by out British comedian Stephen Fry.

López explained that though the movie's monarch would have been a fictional character in any case, the sheer fact of Elizabeth II's celebrity – and the indelible performances that some of the world's best actresses had turned in when portraying her – would have overshadowed any attempt at depicting a Queen of England.

"There we were at the time, with a monarch who had been ruling for 70 years played with distinction by Helen Mirren, by Olivia Colman, by Claire Foy, by Imelda Staunton," López told Variety. "I was like, I'm just dead meat. Who am I going to get? They've all played her, and it's not even her!"

As for those condom wrappers, they were intended to communicate the importance of safer sex practices while acknowledging the fact that a scrip for PReP would never stay a secret if it were prescribed to a British prince.

Moreover, "Once we had passed a certain part in the story, I was like, OK, let's empty out some of the lube,'" López says. "Robbie" – the production's intimacy coordinator, Robbie Taylor Hunt – "and I were looking at it, like, 'How much would they use? Like, well, let's take it down about this much. OK, that makes sense to me.'"

All those tiny-but-telling details are important, of course, since the movie – while being frank about the sexual relationship between the characters – is not, in itself, explicit. Despite the delicacy of the visuals, the Motion Picture Association, which determines how movies are rated, slapped "Red, White & Royal Blue" with an R rating for content that, were the rom-com a mixed-gender couple, would have warranted a PG-13 at most, largely for a slightly lingering comic scene of backside male nudity and some salty language.

Before working with the actors on the film's most tender, and yet also most overt, sex scene, López himself got into bed with Hunt to work out the mechanics in detail to be able to artfully stage and film the intimate moment and make it both restrained and believable.

"There are videos that could, like, ruin both our careers," López related. "Because we were like, 'Alright, we're having sex. What are we going to do? Okay, this pillow goes here. The condom's going to land here. I'm going to do this.'"

"We probably overdid it in terms of the preparation for the scene," López added. "But we also wanted to make sure that we got on to set and we had an answer for every conceivable question."

"Red, White & Royal Blue" is streaming now on Prime Video.