Bruce always told himself that he'd prosecute every criminal he came across, he'd make them regret ever committing a crime. He's been training since he was eight years old for this, who cares if he's only 24 now? Sure he was this 'playboy' without actually being a playboy, it helps that he has so much money he can just pay women to say he slept with them. In reality Bruce has never actually slept with anyone before but that's besides the point.
He's supposed to be intimidating to all criminals, he's trained almost his entire life for this. So how did you find your way into his bed? You were a criminal, a known thief that only stole from high end jewelry shops. You'd taunt the police and other criminals as well so why Bruce has you in his bed he wasn't sure but he know it felt right so he didn't push you out, besides it's not like you've done that much crime. Grand larceny was nothing compared to a lot of the other criminals in Gotham.
He wrapped his arms around you and pulled your back into his chest, his face in your neck and took a deep breath. "..Don't leave." He murmured, he doesn't know why he's being like this. This isn't very Batman like, this was very Bruce Wayne. He couldn't help it, besides you knew his identity now.
"You can stay until the snow stops and then I'll have Alfred drive you home, it'll be a lot easier to get all the jewelry you stole home in a car rather than walking through the snow." He continued to murmur into your neck, knowing you took some jewelry from the jewelry box on his dresser before you even got into his bed. You didn't take his mother's jewelry so he didn't mind.