@NaughtyKitten, reminds me of something that happened with a former girlfriend long ago. Not sure if it helps you. Maybe.
A long time ago at a work function my girlfriend got drunk early and made a fool of herself (and me) during the dinner. I was very mad at her and on the drive home I told her she was going to get spanked as punishment when we got home. She drunkenly tried to give me head as I drove but I wouldn't let her and kept telling her how bad she'd been and how she deserved her punishment. She protested but my mind was set.
Unfortunately when we got home my roommate was there. He was supposed to be out that night. I took my gf straight to our bedroom and we both knew a spanking was not going to happen cause of the thin walls. She grinned at me like she'd won or something. I told her to pull her pants down and get on her knees. She did it cause she knew that I couldn't spank her, so she was just mocking me. I told her to get her head down on the bed with her ass up. Then I spread her cheeks very wide, just staring at her anus wondering what to do. The longer I just stared and said nothing the more she protested "what are you doing? hey! what the hell" in her drunken slurred voice. We'd already had a lot of anal sex which she loved and usually initiated and always with a lot of KY.
So I decided her punishment would be a dry fingerfucking, no lube. I told her this and she protested angrily that I couldn't do it, it would hurt. Still holding her cheeks open I could see her trying to tighten up and I told her it wouldn't matter, that I was going to push my finger in her ass and she had to take her punishment. She tried squirming away but I had her held pretty well. I pushed in all the way deep up to my knuckle which seemed to take her by surprise and take her breath away a little bit, followed my a long UGGGH. I pulled back out and before she could get another protest out of her mouth, pushed it right back in deep again. It definitely was not very smooth cause of no KY. Fingerfucked her rough like that 10 or so times until she dropped onto her stomach and seemed like she'd had enough "punishment".
She passed out pretty quick after. It was fun to discuss with her in the morning. She remembered it but forgot alot about the night. She said she thought the idea of a dry fingerfuck in the ass as punishment was pretty hot. I think she loved it, lube or no. She got me back though another night.
Tell us what other punishments you & your guy come up with.