Love; it can make people do crazy things. It was love that had made Ianto hide the metal monster Lisa had become in the mistaken belief that he could still save her. He’d risked the world and everyone in it because he couldn’t accept that she was already gone.
Equally, it was love that had kept him believing Jack would return after he’d left with the Doctor, despite all evidence to the contrary.
And it was love that kept him here now, painstakingly repairing the coat because Jack would be lost without it.
No coat had ever been loved more.