I watched the video and to me, it looked like she was trying to get away from him and he wasn't having any of it. Looked like she was telling him to get away, and he refused. She balled up her fist and he grabbed her arm. She then tried to hit him with the other hand (again, it appears to me, to get him to back off), so he landed a right cross.

It certainly seems like at the beginning of the video, she is turning her back to him and he is doing everything he can to rub up on her.