Big question is why was the check made out to your girlfriend? Did you request this? Did she take the check? These are important facts. Generally, if you sign a promise to pay and do not pay, you are subject to a lawsuit and being taken to court. Your argument seems to be you received no benefit, consideration or money from the other party. This argument is weakened by the check goin gto your girlfriend because it could be argued that you directed it or received some benefit.
This post should not be considered nor relied upon as legal advice since it is only intended for general overview and informational purposes. Please consult with an attorney on your specific situation in order to determine an appropriate legal course of action.
You are likely responsible to pay this amount to the lender/friend, but you may have the right to request reimbusement from your girlfriend (subject to any romantic or emotional restrictions).
To prevail against the lender/friend, you probably will need to show that the lender/friend is not a "holder in due course" within the meaning of UCC Article III (likely focusing on his lack of "good faith") or that you did not receive "consideration", in that the payment contemplated by the promissory note was not delivered to you.
FYI - I'm not your lawyer, and this isn't legal advice. This is general information designed to afford you a better understanding of the situaton so you may better understand your options, especially when speaking with an attorney.
