1)Allah's Apostle (Pbuh) said, " If a husband calls his wife to his bed (i.e. to have sexual relations) and she refuses and causes him to sleep in anger, the angels will curse her till morning." (Sahih Al-Bukhari Vol. 4 Hadith No. 460 & Sahih Muslim Vol. 2 Hadith No. 3368)
Allah's Messenger (Pbuh) said, " When a man calls his wife to satisfy his desire she must go to him even if she is occupied at the oven." (Al Tirmidhi Hadith No. 1160 & Ibn Ma'jah Hadith No. 4165)
(The man is not obligated to provide for the needs of the wife except once every 4 months, he is also within his rights to withhold sex as punishment. Mohammed himself exercised this right during the controversy over him sleeping with Maria in Hafsa's bed.
The man is not allowed to force the wife into bed with him (there is a hadith detailing that the man should not approach his wife like an animal), however if the man approaches her with kisses she is not allowed to refuse sex. There is no hadith indicating any type of punishment for those who rape their wives. There is no punishment in Shariah for those who rape their wives and as a result husbands are able to get away with this horrific act. Marital rape will not be accepted as a condition for divorce and as a result a woman has to live with the man who has abused her and will most likely continue abusing her.