okay so i'm thinking about the glaring absence of buck at the diaz household when, as we've been talking about, we would expect him to be there because 1) he's legally tied to them and 2) based on everything we know about him, he would absolutely want to see christopher after christopher's been repeatedly threatened in front of him, not to mention the whole fatherhood theme of the episode.
i'm thinking about that, combined with the fact that the last time we saw buck with christopher (in that wonderful dad/son hug) was in 5x02, at a point where buck still thought eddie's relationship with ana was going well (and the episode in which we got “buck takes christopher to the zoo all the time” canon). after which we got the conversation they had about her, where eddie said that ana staying with chris and them becoming "a ready-made family" was causing him to have panic attacks, and buck had some interesting faces in reaction to that.
i thought at the time it'd be a touch melodramatic of me to think that buck would read this interaction as eddie saying that he's not ready for anyone to be encroaching on his relationship with christopher and playing a significant role in both of their lives, because like...we have the whole legal guardian thing...but. in 5x05, we finally got a brief look into what's going on inside buck, and what's going on is that he's very much still prone to some of his old thought patterns: to assuming that he's the problem, to assuming guilt for things that aren't his fault, to removing himself from situations where he thinks he's hurting someone without necessarily talking to the people he assumes he's hurting.
and when harry got kidnapped, i could get it, because ana was still in the picture, and eddie was going home to break up with her, but in this episode, everything is screaming buck's love for chris. he fails to keep his cool when chris is threatened and gets pistol whipped because he steps in; later, you can tell by his face that he understands, to a degree, the desire to rip your own physical heart out of your chest to save your child. he's thrown right into the middle of that situation, which is all about fatherhood and sacrifice, 100% on purpose. and then eddie goes home and takes comfort in chris and buck goes home to taylor and has a conversation with her that is about a million degrees of wrong. not to mention how absolutely glaring all of this is in comparison with 4x14, where buck steps in to take care of chris in eddie's absence, and where we leave him looking on at eddie and chris reuniting with the biggest smile on his face.
and you really just can't help wondering if buck thinks he's not allowed. if he thinks it's not his place to need to be comforted, to need to see chris after an experience like that. if he maybe wants to ask, because eddie's still eddie, but eddie's "being weird" and, last time buck checked, someone assuming a familial role in his and chris's lives landed him in the hospital with a severe panic attack. of course buck's set to be christopher's legal guardian if eddie's ever not there: but right now eddie is very much alive, and buck feels like his family has been slipping through his fingers, and when he goes home he's either painfully alone or faced with his relationship that is clearly deeply discordant, and it would be just like him to talk himself out of asking to be in the one place where he knows where he can safely land.
"did he get to see his son?" / "no, he didn't", and you really have to start wondering at this point just how much buck's agonizing over feeling like christopher is his son and thinking he's not allowed to feel like that.