Yup, this really needs no further explanation.
In September 2012, we got a glimpse into the intimacy Zarry shared in private when Harry walked up to Zayn of all the people in the room (including his secret lover Louis) and handfeed Zayn on camera in front of everyone, including a livestream of fans.
He did not feed his bff Niall, who was sitting right there too. There was something in particular he wanted ONLY Zayn to taste, unsolicited, to the point where he didn’t even hand it to him or ask if he wanted some. He just fed him without words exchanged.
You can tell he was accustomed to doing this type of thing in private, because he didn’t think twice about it. Kind of like the sacred water ritual where he goes out of his way to get Zayn water daily, but also took the cap off and on for him.
Later that day we see Harry wearing the jacket Zayn had been wearing earlier in all the interviews. When Zarry shared clothes, they tended to do it on the same day, and it’s always Harry taking something off of Zayn to wear, like his blue hat.