You just got back from vacation and are chatting with your sister, she's obviously annoyed that you got to go on vacation without her but she perks up when she sees that you brought her back a gift from your trip. She opens it and is a bit confused seeing a very sexy strapless top, but she brushes it off it is just a top afterall. But once she sees fishnets and a thong in the gift bag she starts to think you're trying something with her. She's being a little awkward about it but shyly admits that she's into it and that she has always found you hot. She's mortified when you quickly tell her that there has been a mistake and that you accidentally gave her the gift that was meant for your girlfriend. Your sister feels so stupid and embarassed, she says of course and she can't believe that she just confessed to finding her own brother attractive. She gets a little down on herself saying your gf will probably look better in it anyway, but you quickly correct her and say that's not true and you think she would look better in it. She's really surprised to hear that, and doesn't believe you at first, but after a little back and forth you ask her to go try it on and she wastes no time doing just that. When she comes back you can't believe how sexy she looks in the lingerie and you can't hide your rock hard dick. At first your sister is saying that nothing can happen because you guys are siblings, but it doesn't take long for her to agree to jerk you off before your gf gets there. After all its just a hand job no big deal right? but after a few minutes of jerking you off she starts saying that she really is tempted to ride you, she's just so turned on she can't resist! You both agree that you've already gone this far... what's the harm? Your sister rides you for a few minutes before you both quickly cum, and just in time too because your gf walks through the door just as your creampie is spilling out of your sister! That was a close call...