This past Saturday (May 26) Justin Timberlake and his fiancée Jessica Biel celebrated their much talked about engagement by throwing a cocktail party for their family and friends.

The soiree was organized and hosted by Biel’s stylist Estee Stanley.

A source told PEOPLE:

“Justin and Jessica arrived at the party looking very excited. Jessica was stunning in a long dress with her hair down … Estee created a very warm, welcoming and festive party for the couple.”

According to reports, as well as Jessica’s parents Jonathan and Kimberley Biel, there were 100 guests invited, including celebrities such as Ellen DeGeneres, Timbaland, Amy Adams and Justin’s former NSYNC bandmates JC Chasez & Lance Bass.

After some live music, a deejay took over and guests danced to popular hits, including Madonna’s “Holiday,” Michael Jackson’s “Good Times,” Whitney Houston’s “I Wanna Dance with Somebody” and Usher’s “OMG.”

Justin and Jessica “danced and looked very happy,” the source says.

Afterward, there were speeches, and the source says Timberlake seemed really “touched” by Timbaland’s remarks. “You could tell that they have a very special friendship,” the source says.

A source revealed last month that Justin and Jessica are planning a big summer wedding.

A source close to happy couple said that “Jessica initially wanted a smaller, more intimate wedding, but Justin from the beginning wanted a big wedding and that’s what they have decided on” and they want to “include all their friends” in the celebration.

The source also added “Justin has promised her the best day ever.”