Anakin and Obi-Wan loved an idea of each other but never knew each other.
I read their relationship - and what a happy ending AU looks like - very differently to many.
People who ship them or believe Obi-Wan would be a cool uncle to the twins I think miss the point that the Team is a lie and the love was always misplaced.
Obi-Wan never knew Anakin, not the bits of that mattered. He perhaps knew they existed - his love, his desire for family, his passion, his anger, his fear - but he never understood them. He was incapable of understanding them.
Anakin never knew Obi-Wan, not the bits that made him a real person. Obi-Wan was an idol, an impossible paragon, that Anakin desperately sought to live up and violently resented.
They loved their own ideas of the other, not the reality of who they were.
Anakin's marriage and children would be a fundamental rupture of Obi-Wan's idea of him. Obi-Wan's reaction to the revelation would shatter Anakin's image of him.
I don't think either's love for the other survives that.
Obi-Wan I think would be bitter and heart broken. Turns out Anakin isn't a far better Jedi than he was. Turns out Anakin has been lying to him for as long as it matters. Turns out Obi-Wan failed Qui-Gon, failed the Council, failed Anakin (not as badly, clearly, as in canon, but he still failed).
I think he probably repudiates Anakin - and finally confirms in Anakin's mind that he was never worthy of Obi-Wan's love and he is now never getting it (which Obi-Wan is incapable of giving anyway). It confirms to Anakin that Obi-Wan respected the lie, might one day have loved the lie, but he never respected Anakin, he would never love Anakin.
Even if he doesn't - even if he does the common happy AU thing of (in a massively out of character way) decide he cares more about Anakin than the Jedi, that he is onboard with Anakin's marriage & kids etc - I think it is instead Anakin who rejects him.
Because an Obi-Wan who turns his back on the Jedi, who gives so freely everything Anakin has been desperate for, isn't the Obi-Wan Anakin loves.
Anakin wants something impossible - to be the Jedi he thinks Obi-Wan wants him to be, and in so doing "earn" the love and affection of The Perfect Jedi TM (who by definition shouldn't give it).
Getting that love AFTER having so obviously let down Obi-Wan would I think i) force Anakin to realise Obi-Wan isn't the impossible paragon he believed in and ii) bring up impossible to answer questions of "why now?".
At best they maintain a deeply toxic and resentful co-dependency.
I think more likely is Obi-Wan has his heart broken but maintains his self discipline and spends the rest of his life an empty shell of a human who happens to be the text book perfect Jedi. Anakin also has his heart broken but has a wife and children (and an extended family) and gets to see and experience love again - and learns that Obi-Wan was never going to give it to him.