Warning: Contains SPOILERS for Severance.
Apple TV+'s Mark S.'s (Adam Scott) wife from him as Ms. Casey (Dichen Lachmann) and pushing a forced retirement on Optics and Design chief Burt (Christopher Walken).
While the initial episodes of Severance lean towards a potential romance for Mark and his new severed co-worker Helly (Britt Lower), another romance eventually takes prominence in the Lumon building. From their first meeting, Burt and Irving (John Turturro) are inexorably drawn to each other despite their vying departments, with the pair making flimsy excuses to see each other in each episode. This leads to several tender scenes between the two seasoned Lumon employees, who appear both excited and nervous about the sudden yet powerful connection they share.
The immediate strength of Burt and Irving's bond has given rise to the theory that the pair are actually a couple on the outside in Severance, particularly given the inexplicable sorrow Irving feels at Burt's retirement party. This idea gains significant legs in the aftermath of "Defiant Jazz," which acts as iron-clad proof that Lumon places Severed employees whose "Outies" know each other in close proximity to test the strength of the severance chip. This theory is also furthered by Burt's "transcends time and place" recorded speech in episode 7, which appears aimed more towards Irving than his R&D co-workers despite his Outie having no knowledge of Irving.
Despite only knowing each other for approximately a week on the severed floor, Burt and Irving have a connection that transcends the retro-tech workplace in Severance. While the pair initially bond over a shared love for the artworks of Lumon founder Kier Egan, both Burt and Irving quickly find themselves drawn to each other. This seemingly spiritual link is made all the starker by the fact both men are Lumon stalwarts who appear to genuinely love the company, making their forbidden relationship doubly compelling as they risk their good standing with Mr. Milchick (Tramell Tillman) to steal moments together.
With the confirmation that Mark's wife Gemma is alive as Ms. Casey within Lumon, it could well be the case that Burt and Irving are also together on the outside. Severance has already hinted that Ms. Casey may Mark subconsciously (showing him extra kindness in the severance wellness check), meaning Burt and Irving's connection could be derived from a genuine relationship as Outies as well. This would certainly explain why Irving goes from being a model employee to wanting to "burn" Lumon after Burt's enforced retirement, as well as why Burt's transcendence speech feels like it is aimed directly at Irving (although being recorded for O&D). While Severance is yet to reveal any shred of information on Burt and Irving outside of the severed floor, the two men's clear love for each other could indicate a long relationship in the real world.