Ok,if you insist then...here it is....marry in PI then apply for visit visa w/c last 6 months (try your luck) there is no harm in trying thou...and besides visit visa fee is just 6k php...fair enough,at least you give it a try...because some members grant of visit visa also,just be honest on everything by telling the ECO that you are still 18 and you know the law is 21 for spouse visa.....
TRY !! and good luck (wink)