Resorting to Masturbation If the Wife Is Not Interested
Question

I am a man of a strong desire. I like to have intercourse everyday. When I try to start it with my wife, she refuses for weak reasons like saying she is tired or lazy to make ghusl or because she wants to delay it to the next day. So I have intercourse with her only twice a week. I cannot be patient. So I have to masturbate by my hand fearing to fall into adultery. Although I know it is prohibited, I masturbate about three times a week while my wife is beside me and she knows what I am doing. My wife cares a lot about beautifying herself and using perfumes, but she becomes annoyed if I ask her for sex. Am I sinful to masturbate by my hand? If yes, then does my wife share in this sin?
Praise be to Allah.Husband‘s obligations in Islam
The husband has to treat his wife kindly, because Allah says (interpretation of the meaning): 
{and live with them in kindness.} [An-Nisa’ 4:19]
Part of living with one’s spouse in kindness is having intercourse, which is obligatory upon the husband, as much as is sufficient to satisfy her, so long as it does not harm him physically or distract him from earning a living. 
Wife’s obligations in Islam
The wife is obliged to obey her husband if he calls her to his bed, and if she refuses then she is sinning, because of the report narrated by Al-Bukhari (3237) and Muslim (1436) from Abu Hurayrah (may Allah be pleased with him), that the Prophet (peace and blessings of Allah be upon him) said: “If a man calls his wife to his bed and she does not come to him, and he goes to sleep angry with her, the angels will curse her until morning.” 
Shaykh Al-Islam [Ibn Taymiyah] (may Allah have mercy on him) said: She has to obey him if he calls her to his bed, and this is a duty that is obligatory upon her. … If she refuses to respond to his call, then she is being disobedient and wilfully defiant. … as Allah says (interpretation of the meaning): 
{But those [wives] from whom you fear arrogance [major rebellion or refusal of basic religious obligations] - [first] advise them; [then if they persist], forsake them in bed; and [finally], strike them [lightly].4 But if they obey you [once more], seek no means against them} [An-Nisa’ 4:34] (End quote from Al-Fatawa Al-Kubra, 3/145, 146). 
But it is not permissible for the husband to force his wife to do that for which she is not able with regard to intercourse. If she has an excuse because she is sick or she cannot bear it, then she is not sinning if she refuses to have intercourse. 
Ibn Hazm (may Allah have mercy on him) said: Both slave women and free women are enjoined not to refuse the master or husband if he calls them for intercourse, so long as the woman who is called is not menstruating or sick and likely to be harmed by intercourse, or observing an obligatory fast. If she refuses with no excuse then she is cursed. (End quote from Al-Muhalla, 10/40). 
Al-Bahuti (may Allah have mercy on him) said:  
The husband has the right to enjoy his wife at any time, so long as that does not keep her from performing obligatory duties or harm her; he does not have the right to enjoy her in that case, because that is not part of living with them honourably. But if it does not distract her from that or cause her harm, then he has the right to enjoyment. (End quote from Kashshaf Al-Qina`, 5/189). 
The wife whose husband is harming her by having intercourse too often may come to some agreement with her husband concerning a specific number that she can put up with, and if he does more to such an extent that it is harmful to her, then she has the right to refer the matter to the judge, who may determine a specific number and oblige both husband and wife to adhere to that. 
Resorting to masturbation if the wife is not interested?
Masturbation is prohibited, because of evidence that we have quoted in the answer to question no. 329 . 
There is no sin if the husband is masturbated by his wife’s hand , because it is permissible for him to enjoy her; the same applies if he ejaculates outside the vagina, because of the general meaning of the verse in which Allah says (interpretation of the meaning): 
{And they who guard their private parts. Except from their wives or those their right hands possess,1 for indeed, they will not be blamed} [Al-Mu’minun 23:5-6]  
If the wife will be harmed by intercourse, she will not be harmed if her husband enjoys her in other ways, so she has to allow him to do that. 
Creating a harmonious relationship between spouses in Islam
Both spouses have to tackle this problem in a kind, loving and frank manner; and each of them should understand the rights and duties that they have, because most marital problems stem from ignorance of that. 
Some husbands are keen to satisfy their own desires, and they hasten to do that without caring about their wives or paying attention to their right to pleasure, so the wife finds no enjoyment in it and is put off by it, and it becomes a problem and a burden for her. 
Hence we say, strive to create love and affection between you and your wife; pay attention to her situation and understand her feelings; avoid that which will harm her or hurt her. Tell her of the Shar`i ruling concerning this issue and help her to follow it, and do not put her off, and be moderate in your approach, and you will get what you want.  
May Allah help us and you to obey Him and seek His pleasure. 
For more details, please see the following answers: 193320 , 9602 , 5560 , 83776 . 
And Allah knows best.