Director Matthew López makes an impressive feature debut with “Red, White & Royal Blue,” a love story that skillfully blends the familiar beats of a classic movie romance with the distinctive details of two of the world’s most public young men trying to keep their relationship private. Adapted from Casey McQuiston’s best-selling book, the film is about a British prince and the son of the President of the United States. Both want to keep the relationship secret to protect their privacy, but protecting their families from controversy is even more important to them.

Before that, we have the part we go to movies to see, where initial hostility turns to grudging respect, then some flirty banter, and then a growing recognition that they are deeply in love. Alex Clarmont-Diaz (Taylor Zakhar Perez) is the son of President Ellen Clarmont (Uma Thurman) and Congressman Oscar Diaz (Clifton Collins Jr.). He is passionate about politics but confined to ceremonial assignments, like escorting Nora, the granddaughter of the US Vice President (a charming Rachel Hilson), to the wedding of the grandson of the King of England and next in line to the throne. Alex is annoyed to be relegated to such a photo-op of an event, and does not want to see the groom’s brother, Prince Henry (Nicholas Galitzine). We will find out later why they dislike one another. 

They get into an embarrassing mess (literally) at the wedding reception. In international relations, it seems important to show the world that the two young men are great friends. It’s a classic rom-com set-up, but this is a more ambitious story. López and his gifted cast deftly shift the tone from near slapstick to touching drama. 

The cast is refreshingly diverse, with an understated, almost casual, natural sense that this is just the world these characters live in. Each supporting character is comfortable with who they are, and they do not feel they need to mute their accents or otherwise “blend in.” It becomes a delicately handled plot point when Alex interacts with a Hispanic reporter, always looking for an edge. We see it clearly in how the journalist speaks to Alex in Spanish to assume a kind of kinship and intimacy that Alex parries uncomfortably. The always-terrific Collins as Oscar has a lovely scene showing his son he supports his love for Henry. Oscar briefly references the challenges he and Ellen faced, implying that coming from different cultures made people skeptical about their future. 

These small, careful touches give what otherwise could be a glossy but bland Hallmark-style film some texture, and López’s background in musical theater gives him a good sense of the rhythm of storytelling. A New Year’s Eve party scene is edited with wit and style by Kristina Hetherington and Nick Moore. And a scene when the still-antagonistic couple is stuck in a literal closet is just the right mix of claustrophobic discomfort, a growing realization of their attraction, and, even more surprising, their mutual respect.