The thing about Fitz is that he never expected Jemma to love him, ever. When he started to recognize his feelings for her, he hid them, SURE she wouldn’t feel the same way. You can see the resignation in his eyes when he gives her the oxygen, finally telling her he loves her only because it’s the only way he can convince Jemma to take the last breath.
“I love you, you see?” he tells her in not so many words. “And you’ll never love me back. I can’t stop how I feel, but I can use it for something good. Please, let me.”
And, of course, Jemma has no idea to respond to this except for hugging him and kissing him all over. But when she misses his mouth, Fitz takes it as a confirmation of his fears. He doesn’t expect her to bring him up to the surface; he expects to die.
When he doesn’t die, he finds that he’s not the same man he was. He didn’t prepare for the effects of his hypoxia any more than he prepared to deal with the consequences of his confession, and when Jemma leaves, he takes that as another rejection.
The rejection of his romantic interest was probably a blow, but again, it was something he expected. In the end, it was her apparent rejection of his friendship that hurt the most. He could have dreamed up a Jemma who loved him back, but instead he imagines a platonic Jemma who acts as a bridge between him and the real world. We know that this is Jemmaginary’s function because when Fitz finds another bridge by way of Mack, Jemmaginary tells Fitz that he doesn’t need her anymore.
By the time Jemma DOES come back, hoping to pick up their friendship where they left off, Fitz doesn’t know where to take it. And he could have said, “You didn’t love me back, how could you be so cold?” Instead he says, “We were partners for ten years, then I got hurt, and you decided that I wasn’t worth anything. I was just a random engineer to you, not a friend.” Of course, it wasn’t a very fair thing to say, and Jemma calls him on it. She doesn’t tell him, though, that she left because she thought it would help him.
Does he decide then to say that she should have fell for him, that he deserved her love, that he thought she’d been leading him on? No, because Fitz doesn’t believe any of those things. In fact, he never mentions it again, except in a very vague way when he decides to leave the lab. Even then, he blames himself and not her. “I can’t work with you anymore. I’m not as capable, and the feelings I’ve tried to ignore simply won’t go away. I need to go somewhere else.” He blamed her before, but he doesn’t now, and Jemma is the one who has to fight for their relationship. He leaves anyway.
But Jemma doesn’t stop fighting. She reaches out for him when Real SHIELD tried to take over, and she creates the plan to smuggle the toolbox out of enemy hands. If she hadn’t offered an olive branch, Fitz never would have thought they could be friends again. In fact, he starts to wonder if she wants to be more than friends, but after his awkward flirting falls flat, Fitz decides that friendship is all that Jemma wants, and he’s okay with that.
That’s why he doesn’t want to talk about what happened in the pod when Jemma asks to talk about it. Fitz is embarrassed and sees the conversation as pointless. After all, he has her back as a friend, and that’s what’s most important to him. So when he tells her there’s nothing to talk about, he’s telling her that he gets it and he’s over it. They can forget he ever said anything, as far as he’s concerned. It’s not until Jemma tells him that she wants to talk about it because she feels the same way that he decides to go slow and ask her on a date.
But of course, she is taken away instead.
He works himself to the bone getting her back, but when he succeeds, he clearly thinks they are going to pick up where they left off. He holds her hand, but doesn’t try to kiss her. Instead, he asks for advice on how best to help her and is told that finally going on that date might be the thing she needs. He lays on the charm but stops when she cries, reverting to the friend he’s always been. When she tells him the impossible, that there’s another man, he decides to go back to friend mode permanently.
It doesn’t help, though, when Jemma starts to make advances. She told him, though, that there’s another man, so what does that mean? Fitz tries to back off and save his rival like she asked, but eventually they get into a fight about it. Jemma tells him that he’s being too good, and he asks her what else she expects him to do. He’s her friend and she asked him for her help, so he’s helping her. He doesn’t kiss her until she basically dares him, and even when she kisses him back, he assumes that it’s a one-time thing. She had feelings for him once, but this other man is clearly better, and he can’t compete.
It’s not until later, when the other man is dead and he can barely live with himself, that Jemma asks them to start over. Then, Jemma carefully makes advances again. She knows he’s hurting, so she gives him time to heal while strengthening their friendship. When she has an excuse, she holds his hand. When it feels natural, they kiss. But still, Fitz apologizes for moving too fast, since he doesn’t want to assume anything. She tells him he doesn’t have to wait for her, and that she wants them to move forward.
So, they move forward.
It’s not until then that Fitz starts to believe that Jemma loves him, and it’s wonderful. Not perfect, but wonderful. So wonderful, in fact, that he decides he wants to ask her to marry him. Only he doesn’t, because he’s not sure what her answer will be. Even after everything they’ve been through, he still worries that she doesn’t feel the same way he does.
And when he gets abducted and brainwashed into doing terrible things, he honestly thinks he’s lost her for good. Still, he’s decided that he can’t love anyone else. He cuts off all other romantic ties and resigns himself, AGAIN, to loving a woman who will never love him back. When she approaches him, he can’t even bear to see her disgust. No one is more surprised than he is when she comes and embraces him, and you can see on his face how much it means to him.
One of the beautiful things about the hug is that it’s a testament to the friendship they have and have always had, but Fitz still finds his ways to tell Jemma that he doesn’t deserve her love anymore.
Now, their relationship has been left in a very vague place, but if you look at their history, you can get an idea of what will probably happen: Jemma will fight for him again, just like she always has. Her biggest enemy is usually Fitz himself, but luckily, she knows how to get him out of their way.
I feel like it’s an important thing to point out, not just because it’s an important part of Fitz’s character, but because it’s been extremely consistent throughout the seasons. Fitz has issues with his self-worth, so of course he doesn’t expect people to love him, but he is also kind and compassionate enough that he values other people’s feelings over his own desires. Of course, he’s not perfect, but he always tries to put other people first, even at his own expense.
So, while I feel sad that this is a big character trait of his, it’s also something I love about him. I hope that one of these days he actually has time to accept Jemma’s love for him, but you know, this is a Whedon show.