He didn't expect that question. Or maybe it's just that he'd ignored it so strongly. Either way, he feels an immediate wave of guilt rush over him. Guilt for hiding things from her, guilt for possible betrayal. He loves her, that's true, but he loves other people too, even if he doesn't dare admit that.

So how to proceed? The truth seems the only option. He'd have likely said it anyway in time.

"I'm... I'm sort of seeing someone, Mina. Have been for a while now."