Eat the eight "Bag of Candies" heart candies listed below.
The Bag of Heart Candies needed for this achievement can be bought using Love Tokens during the Love is in the Air holiday. These bags create a random candy with one of the needed phrases. Because of the randomness of the candies and the fact you will need eight different ones to complete the achievement, you may need to purchase several bags to get them all.
This achievement is needed for the holiday's meta, Fool For Love, which is in turn needed for the main holiday meta What a Long, Strange Trip It's Been.