First, learn the basics. Your romantic Tagalog phrases won't do you much good if you don't have a grasp for the basics of the language. Find local Tagalog classes in your area, or go to your library to find instructional books, tapes or DVDs. A solid foundation of grammar and vocabulary will help you speak romantic Tagalog.
Learn some basic romantic phrases in Tagalog. "Mahal kita" means "I love you," "Miss kita" means "I miss you," and "May gusto ako sa iyo" means "I have a crush on you." If you are really serious about this person and you want to spend the rest of your life with her, you can pop the question in Tagalog: "Gusto mo bang magpakasal?" means "Will you marry me?"
Practice speaking Tagalog. Some language education software allows you to hear a native Filipino person speaking Tagalog. "Talk the Talk Tagalog," from Eurotalk, is a great software program that helps you practice Tagalog like a native Filipino. MyLanguageExchange.com offers ways to find native Tagalog speakers with whom you can communicate. You can write letters, text or chat with Filipino people who may be interested in learning English from you. This type of language exchange program is a great way to learn a new language while helping someone else do the same.