Ryan Reynolds and Blake Lively
09/12/2012 AT 12:30 PM EDT
09/12/2012 AT 08:00 AM EDT
When they tied the knot
in a surprise ceremony on Sept. 9, Blake Lively
and Ryan Reynolds
decided to recite vows they'd written themselves.
"They promised to support and love each other and to make each other laugh," a source tells PEOPLE in this week's cover story. The groom "said he would treasure Blake; she said she would adore him. The whole time they were beaming."
The rustic, romantic festivities – held at Boone Hall Plantation
outside Charleston, S.C. – featured whimsical touches, including after-dinner s'mores and a paper-lantern send-off.
The emotional highlight of the evening, however, was when Florence + the Machine singer Florence Welch, a close Lively pal
, performed "Somewhere Over the Rainbow."
bride's eyes "started to well up," says the source. "A lot of people started to well up, actually."