Saw the movie around 2012

A woman visits a town that is by the beach. Her house is not that very big, I think her sister or friend would live there. There was a Christmas tree there and she owned a dog, probably was a labrador. The friend or sister had a kid who was maybe around the age of 10. The woman worked in theater, I think she was a director. At the same that the woman visited the little town, a man also did. He visited his parent’s house and stayed there. In that house, there was also a kid that was around the same age as the other, think that they were friends. I think the man already had a girlfriend. A few days later the man and the woman were introduced to each other. They both liked each other and each kid would try to convince the woman and the man to ask each other out. They wouldn’t do it, so the kids made a plan, they used their dogs as bait to get the two lovebirds to meet. Each kid called the man and the woman saying that something had happened to their dog on the beach and that they better come quick. They end up coming and the kids hide. both the man and the woman see each other and end up realizing that they had been tricked. By this time the man was still with his girlfriend, who i think was also somehow a part of the play that the woman was directing. One day the man comes in and proposes to her. The woman sees and gets sad and just ends up leaving the room. At the end of the movie, the man leaves his girlfriend and goes to the other woman. The very last scene was of them kissing on the beach. The man was wearing a denim shirt.