You may not have many options here.  Irrevocable beneficiaries mean that you have to have his permission to change the beneficiary.  You can always bring the issue up before the court - hey, this is America - in a proceeding to force him to sign over the policy to you or to some one else.  But given the little facts that you have written here it appears that he wants that policy as insurance that he will in fact get paid.  It is unclear whether or not you have formally memorialized the repayment plan but it may be a good idea to have this all in writing and to speak with your attorney.  Good luck.