Depending on how long you're considering doing evenings and weekends, could you say you're studying for something like counselling or financial sales?
Both of these can have high 'per hour' earnings combined with the irregular hours / fluctuations in income. With counselling, you can have the client confidentiality boundary as a way to say 'I can't tell you', and sensible financial advisers do not do anything business related with friends and family in case whatever they advise goes wrong.
If neither of those are plausible with your personality, find something else that leads people to back off. Say you're doing multi-level marketing or worse pyramid schemes, and for only ten grand they can join your 'downline'