Since HaoLin asked if they could come up with something new to bring to his "classmates" the next day, he thought about it for some time and decided to invent a simple new dish that kids would enjoy. He doesn't suspect that his son actually wants to bring that to his crush. He is not ready.

He literally calls Lani over to make the calculations and determine what's the most fitting amount of time they are allowed to spend on Teyvat. TiHao can't help but be a little paranoid, due to how important it is for him to try to fix things with his children, at this point. He can't think of HaoLin going to miss for the next 17 years like it happened to the others who went to Teyvat.

When it's all decided, it's not difficult to convince HaoLin to go with ZhongLi to Teyvat for a bit, whichever excuse they decided to make for the occasion. ZhongLi risks Hao to think it's a date, if he is not careful. XD

He refuses ZhongLi's offering, wanting to deal with his son himself. He picks HaoLin up and carries him to the cold springs, going inside the water, so he can hold the son in it properly. He doesn't care about his own clothes getting all wet and he is close to immune to cold, anyway.
He uses the vial Lani have him — not even he having any idea what that exactly is, but trusting his friend enough to not need to question him.
The special enchanted water clean not just HaoLin's whole body in depth, but even his clothes and also helps with the fur and wounds on his tails. So much that they return to be bright white, like they originally are.

Once dealt with that, TiHao takes HaoLin back to the fortress, for the moment. ZhongLi can have gone with them or return whenever he wants, TiHao never forbid him to.
TiHao thinks the fortress isn't the best place for his son, due to his elements, but doesn't yet have another place ready to take him to. The old underground house in the ex Fengshii is out of question, as he knows his son hates it, and the other house he had built in the woods outside Lianxi… he doesn't even know if it's still there. He plans to go to check, but sure hopes HaoLin could be all right at the fortress.

With the kids and the talkative ones leaving, the fortress returns quickly to its original gloominess and silence. TiHao already feels sort of depressed because of it, even if he pretends that it's exactly how he likes it.
He hardly feels like he belongs to the world at all, feeling more like a lost spirit with some unfinished business he can't ever complete, but still can't move to the next step.

All he can do is to continue his act, pretend to be all right, and just push on towards no real objective, drowning in the misery from all his failures.

As promised, after bringing the seelie brothers in his fortress, he summons Lani there. He also makes sure that Chan actually returned there, but doesn't go to look for him. He knows it would be pointless to try to convince a d*ckhead to do something he doesn't want, he has some experience about d*ckheads.

He leaves the brothers to Lani and goes to investigate on what happened in the fortress during his absence.