Ashley is not surprised

Someone banged on the door.

“Sock!” Taylor rasped around Heather's labia. The brush of one set of lips on the other made Heather's head spin.

The banging continued, shaking the door on its hinges.

“Sock!” Hannah shouted over Heather's groaning and the wet sucking of Taylor's pussy around the strap-on.

“Don't sock! me, Hannah!” Ashley snapped as she marched through the door up to her older sister. Her blonde hair was plastered to her back, and stiff nipples poked through her white bikini top. “Everyone is getting worried down at the lake! I volunteered to come up here myself because I knew the two of you...” She paid no attention to Taylor's face between Heather's thighs. To the cheerleader captain herself, though, Ashley gave a quick smirk with twinkling eyes that dropped Heather's jaw. “The two of you would jump each other if you could make each other come in the time it takes to blink!”

“Wait.” Heather wasn't sure she wanted to be acknowledged right now, but fuck it (mmmm), this was getting weird. “You never told me your sister and Zack's sister were...?”

“Well, I figured it was her business.” Ashley rolled her eyes. This was nothing. She'd seen things Heather's pure, innocent brain couldn't even imagine. “Who do you think answers all the questions I have? Brandon and I would've never figured this stuff out on our own.”

“Ash is my star pupil.” Hannah gave her little sister a one-armed hug without breaking her rhythm, and the two of them beamed at each other. Then Hannah raised an eyebrow. “So how is Brandon treating you?”

Ashley sighed as she reached behind her neck. “He was tickling my ribs the whole ride up, and you know how much I love that. He wants me...” (Heather salivated at Ashley's perky boobs coming out of her bikini cups) “...dripping when we go to bed tonight, but I can't wait that long.”

“Good call.” Hannah turned back to railing Taylor, who was putting Heather through an out-of-body experience. Ashley stepped out of her bottoms and ran a finger over her bald mons and lips. So many to do, and so little time...