The polo player was first romantically linked to Watson in 2008, when they were pictured together at an after-party. However, Boulle has claimed that he chose not to pursue the relationship.
"We had a bit of a thing a while back," he told Heat magazine. "But I have always been an ambitious person and I want to achieve my own notoriety for what I've done.
"That's why I chose not to pursue it any longer, because I didn't want to be the boyfriend of some child actress."
"I actually really like Emma. She's a really cool person. She's a very different person to who she is in the media. That's what I liked about her - she's very interesting."
While Boulle is currently single, Watson is dating her The Perks Of Being A Wallflower co-star Johnny Simmons.
The full interview appears in the new issue of Heat, out now.
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