If by kiss, you mean have the sex and are truly in love with each other... then yes.
Otherwise no.
I think your either in love with X PC/NPC or not, really up to you and your GM on how you want to play it.
And I think True Hope and True Courage are more circumstantial and limited in how long they can protect the user/wielder/"truee"
Love as we can see in the books can last for years, if not more.
Peace is an odd duck, I can see it lasting for a long time for someone like a Buddhist Monk or Zen guy, or a circumstantial basis like Hope/Courage.