IMHO, I will not trust them both. I will book my own accommodation online which is very easy to do. There are loads of hotels in Makati, pension houses which I am sure you'll be fine. You can both catch a taxi from Airport to Makati at around 3-5 pounds.
Let him visit you there, visit his family, know his family better, and sooner or later, you'll discover the truth by your ownself and not from anybody else.
Don't stay in one place like Makati. Visit his family and friends in his province if you want to know him well. It is our culture to introduce our mahal/love ones in our family. Every Filipinos is proud to introduce their boyfriend and girlfriend. If he has allibi, then be very aware and careful.
