I’d suggest that he meant “ambivalent,” but if he couldn’t think of “ambivalent” how could he come up with “controversial”—and if he could think of “ambivalent” why would he have come up with “controversial”?
He can’t mean “controversial,” after all. Wouldn’t that suggest that various observers of his relationship had differing opinions about it? Perhaps if all his writing teachers got together in a room and discussed his relationship, they would disagree?
“Oh, he has a WONderful reLAtionship with WRIting!”
“How can you think that? I call it unHEALthy!”
“Well, it is CLOSE, but I don’t know that it’s unHEALthy…”
“It’s too dePENdent.”
“Well, Writing is so NEEDy…”
“He should get OUT more. It’s too soon for him to be exCLUsive…”
“I still say it’s good for BOTH of them!”
I don’t know how these teachers got so Cosmoesque, but Writing does sometimes have a mind of its own.