if you wanted to be paid, why didn’t you say so? DY +1.
I dont understand why it needs to be made into a big deal, or why he’d need to defend himself or find a desire to smear your name. Perhaps he will right away write you a check, he just didn’t think about it having his son’s discussion on his mind, etc. If you ask for reimbursement and he then denies it or makes excuses, then you can decide how to proceed from there. Til that happens,give him the benefit of the doubt and be dan l’kaf zchus