If you are using your mattress and sheets -you are not spoiling her belongings. A typical argument - was that room always made for her? or from her body? That room is allotted to her for use. Temporally it is being used by you for some reason. It will be your wisdom - how to use it. If you are using her arrangements to collect your come and not spoiling anything in her - do what you would like to do. It will be better if you do it in the bathroom (Only psychological or established moral reasons) or out side.
As long as you wash the sheets before your sister returns.
Do it in the bathroom or behind a bush outside. But not in your sisters room. I wouldn't even be able to wrap my head around that thought if it ever crossed my mind.
Ew no. Just go to the bathroom, lock the door, and do it in there.
Do it! Pics Plz!
yea I kinda want pic too lol
Scroll Down to Read Other Opinions
What's Your Opinion? Sign Up Now!go to the bathroom,you don't want any awkward stains. I'd murder my brother if he did that.
whos gona know?! pft I would and already have done it
If you feel okay with it, and don't leave any sign(s) of what you did, then it's fine.
Nah, that's what the shower is for.
I fail to see a problem with it. Just keep the mess confined to your things, and it's no biggie.
No, that thought wouldn't even come to my mind. It's very weird lol.
I voted C, I don't think its a big deal if you do, just don't get anything on any of her stuff. lol
Just keep clean and quiet
I don't really see an issue with it.
It's not weird at all, a mans gotta do what a mans gotta do.
It's fine.
Ya! Sniff a pair of her panties too
go for it and leave come all over the place.
Sexual Relationships 
Sexual Health 
Most Helpful Guys