Teddy's backstory was further explored on Grey's Anatomy Season 16 Episode 19.
Viewers finally learned the story behind Teddy and Owen's daughter, revealing that the name Allison came from a woman Teddy had an affair with several years earlier.
Kim Raver, who plays Teddy on the veteran ABC medical drama, chatted with TV Line about the shocking reveal and what it means for the future.
"[Showrunner] Krista Vernoff gives us opportunities to pitch storylines at the beginning and end of each season, so I said, 'It would be great if we knew what was making Teddy tick… and we've heard so much about Allison,'" Raver explained to the outlet.
"Then Krista came up with this. I never expected it! And it's a surprise, but then you're saying, 'Oooh! Now it all makes so much sense!' It's such a beautiful piece [of the puzzle that justifies] Teddy's behavior in the present. She's really struggling, you know?"
Raver did not disclose whether she thought Teddy was bisexual. Instead she said that she would prefer to let Teddy's relationship with Allison stand on its own.
"For now, [my feeling is] that love is love for Teddy," she added.
"Her love for Allison was so great that it led her there. I don't know if it defines her."
"Claire, played so beautifully by Rya Kihlstedt, also gave her such an incredible gift of forgiveness [in the storyline]. She really puts the pieces together so beautifully for Teddy to then understand her present situation."
"I think the way we approach love is very much informed by our past in a way, and now that Teddy has a new understanding that you can love two people, what is she going to do with that?"
If you watch Grey's Anatomy online, you know Teddy's past was surprising, and that there are going to be some ramifications from the reveals in the future.
However, since Grey's Anatomy Season 16 has canceled production with 21 of 25 episodes produced, there is a good chance we'll have to wait until Grey's Anatomy Season 17 for more intel.
Teddy is currently in a love triangle with Tom and Owen, and it's likely there were some season-ending reveals planned in that storyline.
Whether Teddy will come clean to Owen, we don't know, but the truth will find its way into his life.
What do you think of all this, Grey's Anatomy Fanatics?
Hit the comments below.
Grey's Anatomy continues Thursdays on ABC at 9/8c.
Paul Dailly is the Associate Editor for TV Fanatic. Follow him on Twitter.