Kakashi basically fell in love with Kahyo, the Ice Style user in his Hiden novel. It's just super secret and she's sentence away.
He totally fell for her, but honestly- his character arc was always so selfless and self-deprecating that I don't think he'd ever marry. Especially as he decribed Hokage as a role of 'Father of all of the Leaf'. Like Boruto said, you pick Hokage role or a wife. You shouldn't try juggle both.