As salamu `alaykum wa rahmatullahi wa barakatuh my dear brother.
Al hamdu Lilah, that you have been married for 7 years and that you have three wonderful children, and I pray that your marriage and your family will continue to be blessed, in sha 'Allah.
Intimate relations between a husband and wife, is at its best, when comunication between spouses is open, honest, compassionate, sensitive and understanding. In fact, intimate relations is a physical expression of what is shared between spouses. If there is any kind of distance in the relationship, if there is less sharing, less openness and less warmth in the marital relationship, it reflects on the intimate relationship. Sometimes, we can get so busy, caught up in all the things we feel oblidged to do, that the effort and time we used to input into marriage, dwindles, and without realizing, something is amiss in the relationship.
The fact that you have to ask your wife why you have to use a condom, signals that there is something amiss in the relationship. From your wifes point of view, she has three children to look after, and not being aware of the family arrangement in terms of whether she has support in the home, and if she works outside of the home, I assume that the toll of taking care of the home and the children, may leave her little bit tired at the end of the day. She might not feel a desire to be as intimate before with you, or she might simply fear having more children. Whatever the reason, there is something wrong if your wife felt that she could not talk to you about her needs. Probably your wish to not use a condom, is the main factor as to why your wife has decided to not discuss it with you, but you also have to consider the factors as to why your wife feels as she does, as in Islam, intimacy between husband and wife is not for pleasure alone.
("And one of His signs is that He created mates for you from yourselves that you may find rest in them, and He put between you love and compassion; most surely there are signs in this for a people who reflect") (Rum 30: 21).
Some women feel that the marriage is incomplete with the showing of love and affection, and feel insecure if they get the distinct idea that they are not satisfying, appreciated or needed. When we are at ease we feel an unblocked flow of feelings. When we are in a state of unease/dis-ease, our minds think "I feel according to my beliefs and/or dreams. By beliefs here it is meant the negative emotions which we become slaves too, determining our perception of reality. At ease, there is an increased halal bonding between husband and wife, which cleanses the body of clogged up negative emotions that create stresses within the body physical. Negative emotions that block the communion of husband and wife include:
Family planning requires both the consent of the husband and the wife, otherwise there is no planning involved.
"Abu Sirma al-Khudri (Allah he pleased with him) reported Allah's Messenger (may peace be upon him) as saying: The most important of the trusts in the sight of Allah on the Day of judgment is that a man goes to his wife and she goes to him (and the breach of this trust is) that he should divulge her secret" (Muslim 8: 3370)
Family planning is not forbidden in Islam, especially in cases where health (and in your case you are both healthy individuals) and the economic situation are key factors. In the time of Prophet Muhammad (SAW), 'azl, coitus interruptus, was practiced as a form of contraception.
"Jabir (Allah be pleased with him) reported: We used to practise 'azl during the lifetime of Allah's Messenger (may peace be upon him). This (the news of this practise) reached Allah's Apostle (may peace be upon him), and he did not forbid us" (Muslim 8: 3388:)
The only problem is that you and your wife come to a joint decision that you are both happy with, and your marital life as a whole will improve, in sha 'Allah.
For further guidance, please try the following links:
• Wife's Emotional Rights
• Intimate Relations: What is Allowed
• Using Contraceptives Without Permission