My hubby is a reluctant spanker and I find it dififcult t get over to him just how much I need to be spanked. It's very easy to get conflicted as well, only yesterday I was demonstrating petulant behaviour in reaction to a comment about my driving. He told me I was being childish which I got angry about instead of steering it towards a spanking.
I think the best way for me to get him in favour of spanking me is to be very nice to him, cocksucking often helps but it's always best if he thinks he's decided a spanking is necessary.