Russell is said to be so smitten with Katy, he's already confessing his undying devotion to her.
He said: "I think I'm in love."
When asked about his relationship with Katy, he added: "I don't think I should be drawn on that."
Apparently he's trying really hard not to talk about the relationship with the public so he doesn't spoil anything.
A friend told The UK Sun: "Russell has had a crush on Katy for ages and was like an excited schoolboy after they got together.
"He really sees her as an ideal catch and is prepared to stop seeing other girls. He doesn't want to talk about it yet as he doesn't want to blow his chances."
Russell and Katy hooked up after the 2009 MTV VMA's in New York last month. They were photographed together over the weekend in London together right before Katy took off to France for Paris fashion week.
A source close to Katy said: "She knows about Russell's reputation but finds him really charming and funny. She's keen to make a go of it."
Could a quickie wedding be next? It seems to be the new Fall trend and Katy is keen on staying up to date on trends. What do you guys think about Hollywood’s newest couple? Will they last or will their relationship fizzle out?