Speaking at the Bafta LA Britannia Awards in Hollywood, the Oscar-winning filmmaker said: "I was a bit surprised at first, but then those things tend to pass me by!"
He added: "I'm delighted for them, they seem to be real soul mates....and I'm sure more than that."
The couple - who have never confirmed they are an item - posed for photos with Danny at the glitzy bash, but rushed inside to the party before reporters could speak with them.
"I'm very happy for them - it seems lovely," Danny told journalists.
But as for any possible wedding bells, the director said he'd be the last to catch on.
"Oh I've no idea, I'm a terrible person to ask about that, I can't give you any gossip on that front I'm afraid," he laughed.