In a large bowl, combine the shredded coleslaw mix, the drained pineapples, and the chopped jalapenos. Set aside.
In a small bowl, whisk together the mayonnaise, rice vinegar, black pepper, 4 tbsp pineapple juice from the can, and 2 tbsp jalapeno liquid from the jar. Whisk to combine.
Pour the dressing over the coleslaw mixture and toss until evenly coated and completely combined.
Cover and place in the fridge for at least an hour to marinate.