ABC News’ Olivia Katrandjian reports:

KISS bassist Gene Simmons married longtime-girlfriend Shannon Tweed Saturday night at an outdoor ceremony on the lawn of the iconic Beverly Hills hotel, according to People magazine.

Simmons, 62, and Tweed, 54, have been together for 28 years and have two children, Nick, 22, and Sophie, 19, who was the maid of honor.

Gene Simmons and Shannon Tweed arrive at The Rally for Kids with Cancer Scavenger Cup - 'Qualifiers' Celebrity Draft Party at Muzik on September 16, 2011 in Toronto, Canada. (Leonard Adam/WireImage/Getty Images)

The 400 guests included Hugh Hefner, Bill Maher and the KISS members. Paul Stanley, one of KISS’ two lead vocalists, was in the wedding party, according to People.

Tweed wore an ivory gown by Priscilla of Boston, a label owned by David’s Bridal which is shutting down after Dec. 31.

The dress was one of three Tweed wore during the event, People reported.

Tweed was also wearing $2.5 million of diamonds for the first dance, not including the engagement ring, according to TMZ.

The jewelry, which included a $420,000 bracelet, was handmade by Michael Raven, TMZ reported.

The couple got engaged this summer when Simmons proposed in Belize on the season finale of reality TV show “Gene Simmons Family Jewels.”

The A&E show will air wedding episodes starting on Oct. 4.

The wedding invitation posted on People’s website read, “Classy Cocktail Attire Requested, although we know some Rockstar attire will be worn.” It was signed by the “soon-to-be Team Tweed-Simmons.”

In the second part of the invitation, the couple’s children drew a family portrait and wrote that the family will now be united as “Team Tweed-Simmons,” and “as annoyingly long as that is, we hope you’re on it.”