Now, it's reported that they are officially dating! To top it off, mother Victoria Beckham totally approves of Millie for her son.
The Sun reports that it's "early days" for the pair.
Millie has always been a big fan of Romeo's, often talking about him on social media.
Once she was asked what she wants for her Stranger Things character Eleven on the show, she replied: "I don't know. Something with Romeo Beckham."
Get it girl.