Had again. It was delightful on a warm afternoon for a cocktail. Since both pineapple and pink grapefruit can vary in sweetness would suggest you may want to take a small taste before adding the sugar syrup to get the correct sweetness - remember the shaking will dilute the sweetness or adjust accordingly.
Refreshing with a nice hint of the tequila and rum. Somewhat tiki style. Would suggest you leave out the sugar syrup if your pineapple is sweet. Perfect with spicy food.