Is it permissible to wear another piece of cloth inside the ihram that is not tailored to fit the body?
Question

                I bought the ihram garments, and the set came with three pieces, two pieces like towels, one for the upper part of the body and the other for the lower part. As for the third piece, it is to be used as a kind of underwear on the lower part. The three pieces are not stitched, but they have two metal snap fasteners for securing the garments.

Does the fact that it has two metal snap fasteners to secure it make these garments unacceptable according to sharee‘ah? I heard that it is not permissible to wear the third piece that is described above – is that correct?
Praise be to Allah.
		The piece of cloth that is worn as a kind of underwear 
		for the lower part of the body, as mentioned in the question, is not one 
		of the things that are prohibited when in ihram, because what is 
		prohibited is wearing pants and, similarly, underpants that people 
		ordinarily wear, unlike the piece of cloth mentioned in the question. If 
		it resembles the izaar (lower garment) in that it is wrapped around the 
		body, and is not tailored to fit the body, then it is acceptable. 

	However, if it is tailored to fit the part of the body that 
	it covers, but it is held together by the snap fasteners, instead of being 
	held together by thread with which the garment is sewn, in the manner of 
	garments that are worn over that part of the body, such as underpants, 
	shorts and the like, then in that case it comes under the same ruling as 
	pants and it is not permissible for the muhrim (pilgrim in ihram) to wear 
	it. 

	See also the answer to question no. 79025. 

	With regard to the two metal snap fasteners for securing the 
	garment, there is nothing wrong with that, so long as the rida’ – or piece 
	that is placed on the upper part of the body – does not appear to be like a 
	shirt or chemise that is tailored to fit the body. Nevertheless, it is 
	preferable to avoid that. 

	Shaykh Ibn ‘Uthaymeen (may Allah have mercy on him) said: It 
	is better not to pin one’s rida’; rather it should be worn over the 
	shoulders. But if he is working as a cook or is serving coffee and the like, 
	and wants to hold his ihram together using a pin, there is nothing wrong 
	with that. But with regard to what is mentioned in the question, about some 
	people fastening it with pins from the neck to the navel,  so that it 
	becomes like a shirt or chemise, I am not too sure about that, because in 
	that case it will resemble a chemise, and the Prophet (blessings and peace 
	of Allah be upon him) said concerning the muhrim (pilgrim in ihram): “He 
	should not wear a chemise.”

	End quote from Majmoo‘ Fataawa Ibn ‘Uthaymeen 
	(22/135) 

	And Allah knows best.