Family Ties/Cum in her pussy without warning her.
Your climax came fast, far too fast for you to warn Heather so you just don't. You plant your feet face down and lift up your sister to shove your dick as far into her cunt as it can go. The action actually lifted her a bit and you blamed the surge of strength from the heat of the moment.
The suddenness caught her off guard and pushes Heather over the edge, her pussy quaking around you as she cums making the experience feel better than you ever imagined. One of her hands shot to her mouth to cover a scream of utter pleasure, eyes tearing up from her climax. After nearly a minute like this, you finally felt your cumming end and your butt fell back onto the bed and Heather fell right on top of you with her tits right in your face.
You had no problem with this position and began to suck on one of them. Heather let out a moan then laid on her side so you can suckle her chest better.
"That was amazing Timmy," She said, running her slender fingers running through your hair. You liked the feeling and reward her by biting her nipple a bit which Heather enjoyed judging from low purr like hum from her. "God damn, if I knew that an awesome fuck was just a few feet away from me I would have fucked you everyday."
With a loud pop, you let out her nipple free and said, "Yeah I would have liked that but better late than never right?"
Heather giggled and nodded. "Yeah better late than never," You went back to sucking her tit but after a while, Heather spoke up again. "Say Timmy, you wanna stay home instead of going on the trip?"
You looked up from her chest and raised an eyebrow, the sight getting a grin from your sexy older sister. "Think about it... we could have the house to ourselves for the whole weekend plus we can spend the entire night catching up on missed time," Your cock went hard at the idea and Heather's soft hand went to fondle it. "We don't need to stay home the whole weekend either. I know this nice little clothing shop with the sexiest outfits for me to try on while you watch, or go to the movies and you can ignore the show while I suck and fuck your cock. Maybe the library with the sexy redhead librarian that gives you that look whenever you come in or best of all...," Heather pulled away and laid on her back to grab something off her nightstand, showing you a picture of her cheerleader team. "I take you to that slumber party that my cheerleader group is planning, the one that I can't go on because of this trip."
You crawl on top of Heather's naked body as you stare at the photo, grinding you cock against her stomach and pillowing your head against her large breast. As the sheer number of ideas play out in your head they all seem very appealing, the last one sounding the most tempting of them all. You've seen the cheerleading team before and while only Nicole can compare to Heather, the rest of them are no slouches in the beauty department.
On the other hand, you have been looking forward to this trip all year. You have no idea when you'll have another chance to go on something like this and Heather is still coming with you so it isn't a total lost.