"You don't need me. You proved you can handle yourself."
Leon Kennedy may be emotionally constipated, but he is not oblivious to women's flirtations or interest.
At the end of RE4R, when Ashley suggests getting Leon put on her detail, his response is not one of being completely disinterested nor dense.*
Let's take a quick look at the scene;
Ashley makes the suggestion, and there is a small smile tugging at his lips as he turns completely away.
He turns back, only halfway, responding with a pained, dismissive 'you don't need me' as if he can't even look at her when saying it. It almost sounds as if there's a quiet exhale, making it seem as if he's trying to laugh; perhaps to deflect from the pain of the idea he isn't needed, or maybe a small scoff to show it.
But then he turns to look at her when he compliments her immediately after, 'you proved you can handle yourself'.
After, it's deflection with a joke to try to ease the heaviness (for him) of the topic, 'even if you could use a lesson in knife safety'.
Finally, this is followed by him ending the interaction [in a way that he knows makes her laugh].
Leon is insecure and possibly even avoidant in his interpersonal relationships. He truly believes that Ashley does not need him and it's likely he thinks that no one needs him, despite the ways in which his superiors use him. Leon wants to be needed, but not just professionally.
Hell, it's possible Leon was hurt at the playful suggestion because he wants to be needed and wanted outside of just how he can protect others and kill.
Despite the above, this man at every turn tries to take on the burden of the world on his shoulders and does everything he can to shield those around him [apart from equally-capable people such as Chris, from what I have seen]. I believe this is because his sense of self worth is incredibly poor and he wants to ensure he does have worth, even though he clearly does and cannot see it.
At the start of his story when we are introduced to him, Leon was late to his job— the one he got to very specifically help people and save lives— and saw his would-be coworkers and friends dead. The ones who weren't dead, he had to repeatedly put back down. (side note: it would be interesting to look into his childhood to see why he was so desperate to be a good guy and save lives)
That same night, he was manipulated and very purposely played by a woman who he thought he could trust. Despite that, he tried to save her life and thought she had died; another addition to his "failure" of saving lives.
Let's not forget the entirety of Raccoon City was bombed into pieces with survivors still inside. Each one of those people lay on his conscience, even though he doesn't even know their names, and it is apparent in everything he says and does.
If you pay attention to Leon's insecurities, the way he deflects Ashley's flirting or even quips back in his own way when he feels secure, you will see that this man is not inept when it comes to emotional awareness. He is very, very aware, and I think interpersonal connections of any type scares him. It seems the majority of people he's ever around either dies, turns and has to be killed by him, or betrays him.
Leon having the ring in RE9 is a sign that he in fact did long for connection and security. But it's very evident in Res media before this game that it also scared him and he did not know how to properly react nor how to properly interact with others in a way that felt safe.
I daresay that the fandom infantilizes Leon in many, if not all, aspects except when it comes to his skill in killing. I think it takes a lot away from his character, development, and journey to do that. The subtly in his action and behavior is what makes it not only so painful, but all the more interesting.
Resident Evil is media that doesn't spell everything out for a screen-scrolling audience, which isn't surprising since the games have puzzles in them. Leon, too, is much like a puzzle. You need to look and see and find the pieces of him that have fallen, see where they fit, and see how he tries to put them back.
This is the first post in a planned series of looking at Leon Kennedy through a microscope! Thank you for reading and I hope to see you around.
*I have seen the claim he is 'trying to be professional' several times, which I heavily disagree with and will address in its own post