Kristin Cavallari is insisting — again — that she and “hot” Austen Kroll are just friends after their recent Mallorca vacation set tongues wagging. “Let’s f–king talk about it,” the “Hills” alum said on Tuesday’s “Let’s Be Honest” podcast episode. “Every f–king DM I’ve had for the last two weeks has been about Austen Kroll coming [on the trip].” The 39-year-old claimed, “There was zero hooking up. We weren’t even flirting or anything. He’s like a buddy.” She dubbed the “Southern Charm” alum, 39, “so respectful and so cool,” as well as a “big teddy bear” with “the biggest heart.” Her pal Justin Anderson chimed in to tell listeners there was…