1 (1.5 fluid ounce) jigger coconut rum
1 (1.5 fluid ounce) jigger peach brandy
2 fluid ounces grapefruit-flavored soda (such as Squirt®), or more to taste
1 lime wedge
Fill a low-ball glass with ice. Pour coconut rum and peach brandy over ice. Top with grapefruit-flavored soda; squeeze lime over soda. Stir.