Here are some sources:
(Note: Different editions of Hadith use different numbering systems, so the numbering in your edition may be a little different. For Bukhari, I'm using the recent Darussalam edition. For Muslim, I'm using Siddiqi's translation. Don't fall for the "I just looked it up in my edition and it's not there" deception being used by Muslim apologists who are embarrassed about this issue!)
Sahih Muslim 4415—Abu Bakr requested permission from the prophet to enter when the prophet was lying down on Aisha’s bed wearing her garment [mirt]. So the prophet gave permission to Abu Bakr to enter while he (Muhammad) was in that state and Abu Bakr finished what he needed and left. Later, Umar came and requested permission to enter and the prophet gave him permission to enter while he (Muhammad) was in that state. So Umar finished what he needed and left. Later, Uthman requested permission to enter to the prophet, so Muhammad sat up and told Aisha, "Take all the clothing that belongs to you."
Sahih Muslim 4472—The wives of the prophet sent Fatimah, the daughter of the prophet, to him and she requested permission to enter while he was lying down on my bed in my robe [Mirt]. He gave her permission to enter and she told him that his wives had sent her to him seeking justice concerning the daughter of Abu Kahafa (Aisha). The prophet said to her, ‘O daughter, do you not love what I love?’ She replied, ‘Yes! I do.’ He then said to her, ‘Then love her also.’ So Fatimah got up when she heard that from the prophet and returned to the wives of the prophet. Then the wives sent to the prophet Zaynab Bint Jahsh…who requested permission from the prophet to enter while he was with Aisha in her robe [Mirt] and in the same state that Fatimah found him in.”
Mishkat Al Masabih, Volume II, p. 1361—She told that the people used to choose: ‘A’isha’s day to bring their gifts, seeking thereby to please God’s messenger. She said that God’s messenger’s wives were in two parties, one including ‘A’isha, Hafsa, Safiya, and Sauda, and the other including Umm Salama and the rest of God’s messenger’s wives. Umm Salama’s party spoke to her telling her to ask God’s messenger to say to the people, “If anyone wishes to make a present to God’s messenger, let him present it to him wherever he happens to be.” She did so and he replied, “Do not annoy me regarding ‘A’isha, for inspiration has not come to me when I was in any woman's garment but ‘A’isha’s.” They then called Fatima, sent her to God’s messenger, and she spoke to him, but he replied, “Do you not like what I like, girlie?” She said, “Certainly,” so he said, “Then love this woman.”
Sahih al-Bukhari 2442—It is related from 'A'isha that the wives of the messenger of Allah fell into two parties. One party contained 'A'isha, Hafsa, Safiyya and Sawda, and the other party contained Umm Salama and the rest of the wives of the messenger of Allah. The Muslims knew of the love of the messenger of Allah for 'A'isha, so when any of them had a gift which he wanted to give to the messenger of Allah he would delay it until the messenger of Allah was in 'A'isha's house. Then the person with the gift would send it to the messenger of Allah while he was in 'A'isha's house. The party of Umm Salama spoke about it and said to her, "Tell the messenger of Allah to speak to the people and say, 'Whoever wants to give a gift to the messenger of Allah should give it to him in the house of whichever wife he is.'" Umm Salama spoke to him about what they had said, but he did not say anything. They asked her and she said, "He did not say anything to me." They said to her, "Speak to him." She said she spoke to him when he went around to her as well, but he did not say anything to her. They asked her and she said, “He did not say anything to me.” They said to her, “Speak to him until he speaks to you.” He went around to her and she spoke to him. He said to her, “Do not injure me regarding 'A'isha. The revelation does not come to me when I am in the garment of any woman except 'A'isha.” She said, "I repent to Allah from injuring you, Messenger of Allah.” Then they called Fatima, the daughter of the messenger of Allah, and sent her to the messenger of Allah to say, “Your wives ask you by Allah for fairness regarding the daughter of Abu Bakr.” She spoke to him and he said, “O my daughter, do you not love what I love?” She said, “Yes indeed.” She returned to them and informed them. They said, “Go back to him,” but she refused to go back. They sent Zaynab bint Jahsh and she went to him and spoke harshly, saying. “Your wives ask you by Allah for fairness regarding the daughter of ibn Abi Quhafa.” She raised her voice until she turned to 'A'isha, who was sitting down, and abused her until the messenger of Allah looked at 'A'isha to see if she would speak. ‘A'isha spoke to answer back Zaynab until she had silenced her. She said, “The prophet looked at 'A'isha and said, ‘She is indeed the daughter of Abu Bakr.’”
For more information on Muhammad's clothing habits, see our "Jesus or Muhammad?" special: