Does Jane's boyfriend exist?

I don't think he does, that's how I understand her character and the ending.

Since the film can also be a satire sometimes, I'd say the story plays a joke on Jane. She and Aaron are two immature characters, smart and noble but also unable to express their feelings clearly or without hurting each other. Act a bit like teenagers. Jane doesn't tell truth all the time, holds back, suppresses, doesn't make first moves, plays at being unavailable.

And I am inclined to think she made up that boyfriend in the end. (He works at the surgeon general's office!?) In order to take that job working with Tom (in the best possible situation though; her brain and his mouth) and be in his vicinity again, seemingly unreachable again, holding back, waiting for him.

She hasn't changed a bit in that seven year time lap. Just forgot Tom for his immoral tear recording probably.

"I'd rather live in his world than live without him in mine."

- That's her.