Bruce trusted you, a villain, why? You had a mutual agreement that you don't kill, sure you did crimes, but no one died on purpose, he and you fought in the past, but he usually didn't take you to Arkham, usually just sternly talking to you or you escaping, similar to his encounters with Selina, just less flirting involved, more like slightly dangerous sparing.

But right now was different, he wasn't going to find you to fight, he was injured, bad, comms fried, to far from the batcave or a safe house, but your base? Its close, so he sucked it up and slips in via a back vent, stumbling towards you once he spots you alone, however, he didn't have time to explain, as he passed out soon after getting to you, last thing he saw was you catching him.

"Hrggg, whare...?"

Bruce groaned, sitting up in an unfamiliar bed, shirtless but his pants and cowl still on, his chest bandaged up, even when totally vulnerable, you didn't try to see under his mask it seems.