Mad Men co-stars Alexis Bledel and Vincent Kartheiser have been confirmed by Bledel's rep to be engaged.  

According to Us Weekly, a source said "Vincent proposed a few weeks ago. She's been wearing her ring. It's huge!"

The couple reportedly started dating last June.

Another friend told the magazine, "They couldn't be happier."

On the AMC series Mad Men, Bledel, 31, played the mistress for 33-year-old Kartheiser's character Pete Campbell, an ad executive. The Mad Men season six premiere will be two hours long and is set to air on April 7.

Bledel has dated a co-star when she was on Gilmore Girls as well. For more than three years she dated Milo Ventimiglia, who was her love interest in the show.

Katheiser had dated actress Rachel Leigh Cook, who starred in the 1990s classic She's All That.

The couple went to Amber Tamblyn's wedding, who starred in Sisterhood of The Traveling Pants with Bledel , when Tamblyn married her beau David Cross.

This is the first marriage for both Bledel and Kartheiser.