Grate about 1 teaspoon of the rind from 1 grapefruit. Cut that grapefruit in half through the middle and squeeze the juice; set aside.
Place the honey in a small microwaveable bowl. Microwave on medium power (50 percent) for 20 to 30 seconds, or until warm. Add the juice and the grated rind. Mix well.
Peel the remaining 3 grapefruit with a sharp paring knife, cutting away most but all of the white pith below the peel. Carefully separate the grapefruit into sections. Remove any seeds and pierce each section in 1 or 2 places with the tip of the knife so the marinade can permeate the grapefruit.
Arrange the grapefruit sections on dessert plates. Pour the honey mixture over the sections. Let stand for at least 15 minutes to let the flavors to blend. Chill, if desired. Sprinkle with the mint before serving.