I'm with this girl that get's seduced by being bit and scratched, i know this because she does it to me and it actually gets quite painful. I'm quite new to the biting and scratching and was wondering if any tips i should have?

you'd be surprised how hard you can scratch and a girl like it, dont be scared. up and down the back girls like - you can go quite hard here depending on the mood/situation, usually aim to make the girl shiver
inner thighs but much more gentle, slightly more than a tickle.
biting depends hugely where you do it, nibble on the neck/around the collar bone at MOST, ears depending on the girl, nipples depending on the girl, thighs depending on the girl.
ive never been with a girl whos THAT into biting, scratching defo but biting not so much. just experiment man, if she hurts you dont be afraid to scratch her kinda hard, and if you go overboard she will tell you.

Thats what i was looking to do, I never been with a girl like this either so why not get other input

nah man, its a good post! interested to see what people say. I've had some experience with both, all im saying is you'd be surprised at how much you can get away with. Especially with a girl whos into this, so go nuts! Dont be scared of hurting her. good luck

it's a mental turn-on for some girls.

just like being spanked.

and i'm not talking little swats.

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what dr. house brings to medicine, i bring to everyday life (an extreme dose of cynicism), don't listen to the curmudgeon!

Biting is fun! I've tried it with a few chicks and I'm yet to have a negative response, the last girl i tried it with, loved it! I'm going to try and incorporate it everytime I have sex now. And I'm not talking nibbles, biting really hard, back of neck/shoulders in rear entry positions, girl laying on her stomach you ontop of her i found the best, I've left bruises/bite marks all over girls, pain can go a long way ! 
One night I got carried away and turned my lay's tits purple/black with bruises, i felt bad about it the next morning, she was in pain but it reminded her of the night we had, which just made her want it more and more, get into it

I wear fangs. Most chicks LOVE being bitten. If the fangs don't scare them away, they want to be bitten.

Scratching is the same way.

And spanking...hell, my ex begged for welts.