Hi, repayment is almost due.
SInce price went down, you only have to pay 0.5
BTC.

I am not sure why you thought that he is going to repay this. Not only is it a bad idea to transfer debt from one entity to another (as Vod mentioned above), but his reputation is not worth the amount of the loan, and you allowed him to receive payment from his signature campaign prior to the loan becoming due causing him to have the ability to extract money from his signature campaign prior to the likely negative trust he will receive when he does not repay you