Being a smart, intelligent gent and not one to get my hands dirty getting all physical at my age, might I suggest you have a word with one of the local prozzies in Aberdeen and hire her (or him, it is 2022) and get him to escort you to his door and make out he's been using his sister's money to pay for this prostitute for the past 4 weeks. Make sure the confrontation occurs in front of as many family members as possible, especially his wife.