One must keep in mind that there is no awrah between a man and his wife. The evidence for that is Aaishah (may Allaah be pleased with her) said: The Prophet (peace and blessings of Allaah be upon him) and I used to do ghusl i.e., from janaabah (impurity following intercourse) from one vessel, taking it in turns to dip our hands into the vessel.
I do no wish to post the entire link, but I read a fatwah that but between a woman and her mahrams, she has to cover her awrah and that it is not permissible to wear tight clothing, either in front of one's mahrams or in front of other women, if it is excessively tight and shows the womans charms. In another fatwah by Shaykh Saalih al-Fawzaan he says that it is not permissible for a woman to wear short clothes in front of her children and mahrams, or to uncover more than is customary in front of them of that which will not cause any fitnah. She may wear short clothes in front of her husband only. The learned scholar, who is now 87, goes on to say that undoubtedly for a woman to wear something tight that shows her bodily charms is not permitted, except in front of her husband only, but in front of anybody else, it is not permitted, even if it is in the presence of other women, because she could be a bad example to others if they see her dressing like this they may do the same.
As for men, the awrah is that part between the navel and the knee, although I think the Maliki mathab is a bit different on this matter.
Again, the rules of this message board do not allow me to post links, look up the article by Muhammad ibn Adam entitled "A Detailed Exposition of the Fiqh of Covering One’s Nakedness (awra)."
I hope this helps.