Confront Applejack about it

As Applejack slips into the water, she dunks her head in to drink some of the water. Big Mac's eyes go wide as he sees the water droplets dripping off his sister's head and hears his earlier thought about something warm and wet replay itself in his mind. The tiny portion right in the back of his head tells him, wait a tick, soesn't my sister have a nice WARM, WET hole of her very own? Liking where this is going you follow her in and settle down admittedly a fair bit closer than you could have. "So what did you want to talk about AJ?"