Put a hidden camera to record all the bad things they did as
evidence. Play the record to your dad and keep a copy hidden
as you might need it in court in future, if need be.
Peep at their passports and find out if all their papers and
sponsorships are legally processed. If not, report it to the
immigration office and have them deported for good. Work on
lope-holes, such as to see if their stay required them to be
employed and they are not. I believe your dad can only
sponsor one person, unless they are registered employees.
Follow them on the next trip home and on the trip back to
singapore changi airport, put some illegal stuffs (how illegal the
stuffs can be depend on how bad you are). Do that in the
China airport during baggage check-in, not in Singapore
airport. This trick can serious kick their ass back to China
and deported for good.
Meanwhile, ask your maids (or yourself) to spits saliva on their
food, take their clean clothes (underwear is best) and mop the
floor and put it back, buy some laxative and flavor it on their
food. Just make their stay uncomfortable.
Last advise, find or hire a charming guy to seduce that woman
and ultimate catch them on bed with photos. That put some
sense in your dad. I am not sure the law now, but if your dad
divorce her because of her misconduct and your dad can prove that
he has many financial burdens, the court might nullify the
support. But before your dad divorce her, might sure all
properties (those already paid in full) are back to your dad's
nominee names, giving excuse that your dad lost money in business
and these properties are mortgages.
Let justice be done.
