How do castaway Sims from Sims 2 castaway fall in love?

Two Sims (male and female) get to be best friends. You must then at 100 relationship points, click on the "Propose" under Romantic. If that doesn't work, craft a Marriage Beanie on the bamboo crafting table under clothes then hats and then craft two Aloha Wedding Leis from either crafting table under clothes then jewelry. Put the beanie on the boy, and they both get a lei. Then you will be able to get hitched.