Is it legal to tell partner to stick to agreement or else?

If your partner doesn't abide by your contract, you can sue him to enforce it and/or for damages caused by his breach.  You may also be able to dissolve your partnership.  These proceedings may or may not result in the disclosure of embarassing information about him.  However, it is not a good idea to release information outside of the context of a lawsuit, simply for the purpose of embarassing him.  Depending on what information is released and what problems the disclosure causes, you are probably not liable (but could be in some cases) for such disclosure as long as it is true, but why take the chance of getting sued over it?