Sly,
This is obviously a simplistic answer to a question that must be far more complex, but here goes...
Write down the possible decsions you can take, and think about the pros and cons of each.
Decision 1
You go back to your ex.
Decision 2
You stay with your new man, but say nothing about your feelings in the bedroom.
Decision 3
You stay with your new man, but you talk with him about your feelings.
Only you can predict the most likely outcomes of each decision (and even then you could be wrong).
However, IMHO the decision that is most likely to leave you feeling unfulfilled and less happy will be Decision 2.
Decisions 1 and 3 both require active change - whether it's dumping your new boyfriend, or being honest with him.
Here's the good news. You have the chance to take more than one of these decisions. For example:
You decide to be honest with your boyfriend. Choose a quiet evening when you don't have the kids around and talk to him. Take it slowly, and do not expose him to the full "gothic horror" of the BDSM world all at once
Broadly speaking he could react in two different ways.
- He might not be interested...in which case you're in the same situation as Decision 2. Now you need to decide if you can continue to live with him on those terms.
- He may show some level of interest - right up to the point where he might embrace your wildest dreams and the two of you begin an amazing journey of discovery.
In fact these two reactions are the extreme ends of a spectrum - as long as you give him a "soft landing" on your fantasies it's unlikely that he will be totally uninterested. But it's equally unlikely that he will immediately tie you up and become the Dom of your dreams. You need to manage your own expectations, and enjoy small steps towards something that makes you happier in the bedroom.
If your new boyfriend is "less interested than you can tolerate", then you still have the option to take Decision 1, and go back to your ex-husband.
I'm sure you're familiar with the phenomenon that former partners often seem more acceptable after some time has passed. Presumably you split up with this guy for a good reason. You need to be sure you're not just going back to the same situation - especially as there are children involved.
So the short version is...have a chat with your new boyfriend and tell him how you feel.
Hope this helps.
Cheers,
Stanley