The problem is that you are perfectly comfortable with your current cuddle buddy and you don't want to make it a full on relationship, but you don't want to lose him or her either. Now that you realized you are stuck in this weird phase, it is my job to clear things up for you.
There is a fine line between part-time cuddle buddy and full-time cuffing.
This is almost as bad as you guys having a kid together.
The best part of having a cuddle buddy is that you have someone to keep you company on these brisk, cold nights, while still being able to actively look for other partners.
Are you interested in being tied up or otherwise restrained (bondage)? And is the type of punishment you're interested in physical (e.g. [related_post] Seeing as you mentioned that your partner isn't into hitting you, I assume you enjoy pain.