How would you feel if your friend had sex with your brother or sister?

I would ask if I could join in next time.

Who he sleeps with is his business. The only time I'd butt into his relationships at all is if the person were doing something behind his back that he should be aware of. I might find it odd if he dated a friend of mine, however, because all of my friends are a little too old for him to actually date.

Depends on the friend.

Meeeeeeeeeeeeeh. I wouldn't like it and the only person I consider a friend is aware of that and wouldn't do it. I like to keep my friendships away from my family, I like the seperation in social groups. So I would be irritated by him for it.

Only child

If people genuinely care for each other, then I dont care. If my sister and my friend are happy, then I am too. But if she gets screwed over, PUMP PUMP KILL BITCH!!!

i would wanna no it all about her sex and dick sucking see if she would get horny if she see a dvd on in my room with my dick out would she rub and get badder i would give her tips find out what she loves then one day when we realise we need each other then id fuck her and get my mate to join in and get her gagging for me

I wouldn't care at all who my younger brother decided to have sex with, his business and not mine. I might feel differently if I had a younger sister though.

Meh, my siblings and I aren't that close. I think I'd feel more strongly for the friend if they were close to me and had sex with my evil sister, though. (I don't want to get into details, but she's not a nice person to be around.)

If he or she was a good person who wouldn't hurt my sis/bro, then I don't think I'd mind.
But having no siblings, perhaps I would feel differently if I did.