Mary Lynn Rajskub Cracks Marriage Code

The only password Mary Lynn Rajskub had to remember Saturday: I do.

The usually sour-faced 24 star, who plays computer whiz Chloe O'Brian on the Fox drama, was all smiles this weekend as she tied the knot with personal trainer Matthew Rolph in Vegas, E! News has confirmed.

A mere 20 guests were in attendance to watch the bride, clad in a satin Nicole Miller gown, swap vows with her longtime love, who donned a Hugo Boss suit for the occasion, at Planet Hollywood Resort & Casino in Las Vegas.

The couple's 1-year-old son, Valentine, toddled down the aisle with them to the tune of—what else?—Elvis' "A Little Less Conversation."

"We didn't know that getting married at a casino in Vegas with Elvis could be so romantic," Rajskub told People, which first had the nuptial news. "Our wedding was beautiful, spontaneous and intimate."

The newlyweds continued to celebrate into the wee hours with pals, included It's Always Sunny in Philadelphia producer-star Rob McElhenny and his wife-costar, Kaitlin Olson, at Koi Las Vegas.