I think there is a huge difference between forgiving and putting oneself back in a situation to be hurt in again. There may also be different types of forgiveness. We can forgive-as in let go of our woundedness-without forgiving-as in forgetting anything ever happened and being repeatedly slapped. Therefore:
SLAP
I forgive you. *turns other cheek*
SLAP
I still forgive you. *steps out of situation*
And that is ONLY if turning the other cheek means forgiving. Actually that passage is talking about going the extra mile.
Matthew 5:39 But I say unto you, That ye resist not evil: but whosoever shall smite thee on thy right cheek, turn to him the other also.
Matthew 5:40 And if any man will sue thee at the law, and take away thy coat, let him have thy cloke also.
Matthew 5:41 And whosoever shall compel thee to go a mile, go with him twain.
Matthew 5:42 Give to him that asketh thee, and from him that would borrow of thee turn not thou away.
Matthew 5:43 Ye have heard that it hath been said, Thou shalt love thy neighbour, and hate thine enemy.
Matthew 5:44 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you;
Matthew 5:45 That ye may be the children of your Father which is in heaven: for he maketh his sun to rise on the evil and on the good, and sendeth rain on the just and on the unjust.
Matthew 5:46 For if ye love them which love you, what reward have ye? do not even the publicans the same?
That is talking about going above and beyond to be nice to people, not letting them deliberately do something against you repeatedly and just forgetting about it.
Now, the verses about 70x7 are about forgiving, yes. BUT, if God ONLY forgives us when we repent (and according to what I've heard, salvation is based on repentance for that very reason), can He ask any more of us? Therefore I think this verse is talking much more about letting go of hurt, for our own sake, rather than letting someone walk all over us.
The only time I've heard this adequately preached was when someone said: I forgive them. I still love them, even. But some people I just love a lot more when they are WAAAAYYYY over there. (not close enough to hurt him again)