Idk she probably had to remind him not long before that episode that when she's showing signs of insecurity about her looks it would be nice affirm her by telling her a compliment or something like that. Although that could be too complicated for simple ian so maybe something like that but in simpler instructions. And I do not believe that he's ever bought her anything without her putting idea in his head or straight up telling him to buy specific thing. That includes that birthday cake and also cruise tickets and also the engagement ring as in she 100% suggested if he does not propose she's leaving. He's too cheap and socially retarded to think of any of these things on his own.He spontaneously called her attractive on the last pod. She followed it up by saying what he found attractive was actually her looking like his male former friend (max). She basically called him gay in response to a spontaneous show of love/attraction. In the past, we know he did the surprise cruise thing and more recently he's gotten her stupid grocery store b-day cakes, which is pretty normal. Ian is/was never the person you'd get the "running bath with roses" fantasy from. If anything, her sheer presence induces apathy because of how soul-sucking and emasculating it is. Dont forget that they have been together day in and day out for nearly a decade, you don't grab someone's favorite snack for them at the store when they're right next to you.
Not trying to say he's a fantastic husband who we'd all want to be with, most women don't want a weak-willed simp. But he's not treating her like shit. He's a hollowed out SSRI schizoid at worst.
He chose bad moment for the compliment bc she just wanted everyone to confirm she totally did look like maxmoefoe which lol what a throwback. It was a thing yaoi-loving idubbbz/cancer crew fans used to say in ~2017 to cope with the fact that neither ian nor max were totally gay for each other. "Okay now ian has a gf too but doesn't she kinda look like Max tho?? Omg he's so in love with Max that he found a female clone of him!! uwu" I've never seen the resemblance and found it cringe as hell but it made a lot of idubbbz fangirls instantly love her for that thing alone.