I think its important to remember that its not like every guy has a hidden desire to tie/spank/whatever the girl that they're with. That's not to say I had anything against it... it was more that I had never really given it a consideration beyond a couple playful slaps on the ass when she was on top.

When she first asked me to spank her I assumed she meant like, I dunno, once or twice. Then when the light went off I was like, "ohhhhh... Okay. I guess I can do that." The thing was, I had no idea what she was expecting me to do, so I was super nervous and honestly probably was also "extremely cautious." I still sort of had the mindset of like, I guess she thinks a little playful spanking is hot. We hadn't done anything like real spanking in the 3 years leading up to that night, so it's not like I was expecting it to drive her wild.

One thing that really helped for us was that, after a time, she was really open about it. She was clear that it DID drive her wild, that she wanted it, that she liked me being in control, and probably most importantly, that I was doing a good job.

I still felt pretty foolish doing it for a long time, for lack of a better phrase, I played along because she liked it. She didn't awaken a deep desire in me to suddenly be a dom or anything, but she gave me the confidence to do something she found hot.

It also didn't hurt that suddenly she was having way more frequent and intense orgasms. She also made sure to try to keep things even and give me a night that was "my turn" in return every time.

Almost 5 years later we've never really ventured too far beyond what you mention in your post, but we're pretty open about making sure we can scratch that particular itch for her once in a while. I'm sure your bf wants you to be happy and will get there in time too.

TL;DR - gf gave me time to adjust and gave positive feedback, now she's my wife and I spank her on the reg.