'Buffy the Vampire Slayer' and even 'How I Met Your Mother' fans were recently elated to hear that the series would re-unite star Alyson Hannigan with two-time on-screen love interest Seth Green for an upcoming installment of the show's (likely) swan song season.  The initial announcement gave a few details of Green's role as a forgotten friend of Marshall and Lily from their college days, but how would you like to see the pair officially re-united on the set?

Willow and Oz shippers rejoice, Alyson Hannigan and Seth Green are back together!  Sort of.  Hannigan remains married to fellow Whedon-verse player Alexis Denisof (another occasional 'HIMYM' guest), but Hannigan herself has tweeted out the first photo of the 'Buffy' reunion on set.  The shot below doesn't give away much more than we already knew, but does feature Hannigan decked out in her "Goth Lily" duds, known to fans as indicative of her college years at Wesleyan.

According to the initial breakdown, Green's role is that of "creep" Daryl LaCoutre, a former Wesleyan classmate of Marshall and Lily’s.  Daryl viewed the couple as his best friends, though 12 years later they have little memory of the man, and find themselves unnerved that he continues to live by the campus obsessing over a reunion with them.

Take a look at Hannigan's Twitter photo of the 'Buffy' reunion below, and tell us what you think of the final season of 'How I Met Your Mother' in the comments!

How I Met Your Mother Seth Green Alyson Hannigan
@alydenisof / Twitter