A heartwarming video has emerged from the US of a man surprising his girlfriend with a flashmob proposal.<br /><br />The footage, captured in Pennsylvania on February 3, shows the woman sitting on the back of a car whilst her cousin plays her favourite song on the guitar. Then, all of a sudden, the car moves and she sees her relatives and friends dancing together. <br /><br />Finally, the boyfriend appears and gets her out of the car to ask her hand in marriage. <br /><br />''When we get to the bottom of the driveway I see my mom and her husband Jon I remember thinking this is silly. At the next part I see my Dad and his Fiancee, Leona, and I was in total shock,'' the woman later wrote online.<br /><br />''I was flat out confused until I saw all four of my best friends all come out together until I realised it was a proposal.''<br /><br />''After that, more and more friends and family kept joining in and I could not have been more shocked and happy to have everyone come out and participate in this big performance.'' <br /><br />''Not only was I emotional knowing this is a proposal, but I began tearing up just seeing all the support from everyone. It was really special seeing all they were willing to do to show how much they love us,'' she added.