Ian Somerhalder Engaged to Nikki Reed
01/15/2015 AT 06:45 PM EST
The Vampire Diaries star and the The Twilight Saga alum – a true match for fans of the supernatural – are now engaged about six months after their romance first made headlines in July, a source tells PEOPLE.
"They're so happy!" the insider says.
One of their first outings as newlyweds-to-be? The Golden Globes party circuit, where Somerhalder was spotted wrapping his arms around his fiancée and getting affectionate at the InStyle and Warner Bros. afterparty. (When asked about her date for the evening, the actress told PEOPLE she came in a group.)
Just last month, they spent the holidays together, hitting the slopes with family in Sun Valley, Idaho – just one of many adorable sightings for the couple since they stepped out.
Somerhalder is "very serious" about Reed, a source told PEOPLE in August – which was supported by their expanding furry family.
Their wedding plans come nearly a year after Reed announced she was divorcing American Idol musician Paul McDonald in March 2014. Somerhalder was last linked to The Vampire Diaries costar Nina Dobrev, whom he split from in May 2013.
Reporting by ELIZABETH LEONARD and AILI NAHAS