It helps that Daniel Radcliffe's girlfriend Erin Darke is also his best friend, in light of Zoe Kazan's nipple-note exchange with the actor.

Daniel Radcliffe's girlfriend is unfazed with the entendre between her beau and Zoe Kazan, both starring in new movie "What If."

Zoe Kazan's nipple-note pasties were short and sweet: "Hi Dan." Radcliffe took it in stride, and even considered responding with notes on his rear end.

Radcliffe and Kazan co-stars in the romantic comedy about a guy who falls for someone already taken, and both admit they made it a point to make the sex scenes eventful. The two made the experience less awkward by finding unique ways of communication.

Daniel comments during a red carpet interview with UK's Daily Mail: "We had a lot of fun. Zoe wrote me a message on her nipple pasties which said, 'Hi Dan'. It was a concise message. It was fun, it was a good couple of days."

Even though Daniel Radcliffe's girlfriend will likely decline to comment, the "Harry Potter" sensation is confident she understands. On his response to Kazan's nipple message:

"I tried to write, 'Hi Zoe' on my bum, but I seem to remember trying to do it in a mirror. My handwriting is not great at the best of times. Trying to do it backwards on the back side of me, it would not have gone well."

Radcliffe isn't putt off when it comes to nude scenes; he's already performed in the buff in "Equus."

"I've had much worse nude scenes in my life. It was kind of a fun scene because it's about skinny dipping and actually that night, it wasn't warm but it wasn't nearly as cold as I have felt it be in Canada at that time of year, so it could definitely have been a lot worse." (yahoo.com)

Looks like Daniel Radcliffe's girlfriend will just have to keep her eyes closed in some scenes, when "What If" debuts in theaters this month.