Sarah Cooper survived through four years of final exams, term papers and stress as an undergraduate in American University's School of Public Affairs.  But when the soon-to-be graduate stepped forward at her school's commencement ceremony over the weekend she got more than just her diploma and a handshake.

What Cooper got instead was the marriage proposal of a lifetime, courtesy of her boyfriend, and fellow American University graduate, Sam Miller.

Miller, a newly minted graduate of the university's school of communication, halted the Washington, D.C. university's commencement ceremony on Sunday morning by getting down on bended knee just as his bride-to-be walked across the stage in her mortarboard cap and purple gown.

In video of the proposal posted on YouTube by the school, Miller is seen waiting in the wings as Cooper accepts her diploma and then, to the audience's delight, walking to the front of the stage.

On bended knee, and barely audible above the excitement of the crowd, Miler got down on one knee to say, "I have a question… Would you marry me, Sarah Cooper?"

Cooper did not hesitate in her response, giving an affirmative nod and running towards her fiancé for their first kiss as an engaged couple.