Muhammad married Khadija at the age of 25 and remained faithful to her for 20 years. After her death, and in the span of 10 years, he married 9-11 (some say 14) women.
Narrated Qatada:
Anas bin Malik said, "The Prophet used to visit all his wives in a round, during the day and night and they were eleven in number." I asked Anas, "Had the Prophet the strength for it?" Anas replied, "We used to say that the Prophet was given the strength of thirty (men)." And Sa'id said on the authority of Qatada that Anas had told him about nine wives only (not eleven). (Sahih Bukhari 1.268, Sahih Bukhari 1.282)
Other hadiths: A Muslim wrote on soc.religion.islam: "they claimed by several hadiths in Bukhari that Muhammad cursed a left-handed man who eating with his left hand, and cursed a child passing in front of him while he was praying and caused both of them to be crippled! By inventing sexual miracles they insulted the prophet and his wives with foolish and shameless stories. By inventing Miraj stories (miraculous ascension to heaven with the body) they present Muhammad as a union stewart bargaining with God on the number of daily prayers; but on the other side insulting him, implying that he could not understand that his followers cannot practice 50 prayers a day (a prayer per 28 minutes). After taking advice from Moses who was a resident of the 6th heaven, he reduced them to 5 prayers a day- after five times going up and down between Moses and God! To praise Muhammad, some claimed that in the generations from Adam to Muhammad there were not any disbelievers among his ancestors. To justify their lie, they claimed that Azar was not Abraham's father (al-An`am 6:74). To prove that Muhammad was the greatest prophet they even claimed that he was created from light, he had no shadow, his body will not rot in the grave, God created the entire universe for him, he will have the highest intercession authority in the hereafter, and so on...'' (Edip Yuksel)
Narrated 'Urwa from 'Aisha:The wives of Allah's Apostle were in two groups. One group consisted of 'Aisha, Hafsa, Safiyya and Sauda; and the other group consisted of Um Salama and the other wives of Allah's Apostle. The Muslims knew that Allah's Apostle loved 'Aisha, so if any of them had a gift and wished to give to Allah's Apostle, he would delay it, till Allah's Apostle had come to 'Aisha's home and then he would send his gift to Allah's Apostle in her home. The group of Um Salama discussed the matter together and decided that Um Salama should request Allah's Apostle to tell the people to send their gifts to him in whatever wife's house he was. Um Salama told Allah's Apostle of what they had said, but he did not reply. Then they (those wives) asked Um Salama about it. She said, "He did not say anything to me." They asked her to talk to him again. She talked to him again when she met him on her day, but he gave no reply. When they asked her, she replied that he had given no reply. They said to her, "Talk to him till he gives you a reply." When it was her turn, she talked to him again. He then said to her, "Do not hurt me regarding Aisha, as the Divine Inspirations do not come to me on any of the beds except that of Aisha." On that Um Salama said, "I repent to Allah for hurting you." Then the group of Um Salama called Fatima, the daughter of Allah's Apostle and sent her to Allah's Apostle to say to him, "Your wives request to treat them and the daughter of Abu Bakr on equal terms." Then Fatima conveyed the message to him. The Prophet said, "O my daughter! Don't you love whom I love?" She replied in the affirmative and returned and told them of the situation. They requested her to go to him again but she refused. They then sent Zainab bint Jahsh who went to him and used harsh words saying, "Your wives request you to treat them and the daughter of Ibn Abu Quhafa on equal terms." On that she raised her voice and abused 'Aisha to her face so much so that Allah's Apostle looked at 'Aisha to see whether she would retort. 'Aisha started replying to Zainab till she silenced her. The Prophet then looked at 'Aisha and said, "She is really the daughter of Abu Bakr." (Sahih Bukhari 3.755)
Narrated 'Ubaid bin 'Umar:I heard 'Aisha saying, "The Prophet used to stay for a long while with Zanab bint Jahsh and drink honey at her house. So Hafsa and I decided that if the Prophet came to anyone of us, she should say him, "I detect the smell of Maghafir (a nasty smelling gum) in you. Have you eaten Maghafir?' " So the Prophet visited one of them and she said to him similarly. The Prophet said, "Never mind, I have taken some honey at the house of Zainab bint Jahsh, but I shall never drink of it anymore." So there was revealed: 'O Prophet ! Why do you ban (for you) that which Allah has made lawful for you . . . If you two (wives of Prophet) turn in repentance to Allah,' (66.1-4) addressing Aisha and Hafsa. 'When the Prophet disclosed a matter in confidence to some of his wives.' (66.3) namely his saying: But I have taken some honey." (Sahih Bukhari 7.192)