The 3 "F"s to maintain a love triangle.
2.Foolish (or be a fool)
3. Fukanzenna Ketsumatsu (Incomplete Closure)
Excellent advice Keima-sama. But aren't these the same tips for two-timing? Anyway if it all doesn't make sense please read Chapter 126 of The World God Only Knows Manga. I can't wait for the anime's second season!