And McCord can't wait to attend the upcoming nuptials.
Introducing Oriolo as "the future Mrs. Lutz", she told partygoers, "I'm very, very excited about her big day next week."
Kellan, who threw his brother a bachelor party in Sin City earlier this year (11), was not present for the weekend bash - he is busy filming scenes for the upcoming Twilight sequel Breaking Dawn in Canada.
McCord sparked reports of a reconciliation with Lutz last week (19Apr11) after the on/off couple was spotted arriving together at an airport in Vancouver.
The stars split in October (10) after two years together.