Take a nutmeg and cut it into 4 pieces.
Now we are going to use the elements to ensure trust:
Bury the first quarter somewhere where it can be left undisturbed, throw the second into the wind off a high building or a cliff if you live near the sea, burn the third (in your Beltane fire), and boil the last to make an elixir. Drink a sip from the liquid and then retrieve your last piece and keep it with you at all times (including putting it under your pillow at night).
You have done all to ensure your partner remains true for as long as you are apart.