The two actors were seen chatting while attending the London premiere of their biblical epic on Monday night (31 March).
Perhaps Russell was telling Emma how much his kids like her?!
Russell told an Australian radio show this week that sons Charles, 10, and Tennyson, seven, thought he was a cooler dad now he'd met Harry Potter star Emma, who played Hermione in the magical franchise.
"I'm getting better in their eyes now that I've worked with somebody like Hermione," he told the Kyle and Jackie O Show.
"At one point they were supposed to come to the set with me, but then their plans got changed and so they didn't come to set and they were just heartbroken."
Russell and Emma star together in the epic Noah, which is loosely based on the story of Noah's Ark. It also stars Jennifer Connelly, Ray Winstone, Douglas Booth and Logan Lerman, Emma's co-star in The Perks of Being a Wallflower.
As well as meeting up with Emma, Russell was also seen giving fellow actor (and his Les Miserables co-star) Hugh Jackman a friendly hug on the red carpet before they posed for some pictures together.
We know. Maximus Decimus Meridius and Wolverine together. Amazing.
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Watch a trailer for Noah below: