I would like to know if it is allowed for a man,  when he is married to two wives to take the second wife every time if he  will travel, even if the first wife cannot go because of her children.  What can she do if she feels that he do not want to divide his time  equally between them. Please advice a good website with answers on  polygamy. 
   
Praise be to Allaah.               
     Firstly: 
     Allaah has enjoined justice and fairness in all things. He      says (interpretation of the meaning): 
     “Allaah commands justice [and] the doing of good”      
     [al-Nahl 16:90] 
     Ibn Jareer al-Tabari (may Allaah have mercy on him) said: 
     In this Book that He revealed to you, O Muhammad, Allaah      enjoins justice, which is fairness. 
     Tafseer al-Tabari (17/279). 
     Allaah has forbidden injustice and wrongdoing (zulm) to His      slaves, and He warns those who are unjust or do wrong of punishment in this      world and in the Hereafter. 
     It was narrated from Abu Dharr (may Allaah be pleased with      him) that the Prophet  (peace and blessings of Allaah be upon him) said,      narrating from Allaah, may He be glorified and exalted: “ ‘O My slaves, I      have forbidden zulm to Myself and I have made it haraam among you, so do not      wrong one another.” Narrated by Muslim (2577). 
     Allaah has enjoined justice and fairness between co-wives,      and there is a warning against wronging one of them at the expense of      another. Allaah says (interpretation of the meaning): 
     “And if you fear that you shall not be able to deal justly      with the orphan girls then marry (other) women of your choice, two or three,      or four; but if you fear that you shall not be able to deal justly (with      them), then only one or (slaves) that your right hands possess. That is      nearer to prevent you from doing injustice”
     [al-Nisa’ 4:3] 
     Shaykh ‘Abd al-Rahmaan al-Sa’di (may Allaah have mercy on      him) said: 
     i.e., the one who wants to take two or three or four wives      may do so, but no more than that, because the context of the verse reminds      people of the blessings of Allaah, so it is not permissible to add anything      to the number that Allaah has defined, according to scholarly consensus.      That is because a man’s desire may not be fulfilled by one wife, so it is      permitted for him to take more, up to four, because four is sufficient for      anyone, except in rare cases. However, that is only permitted to him if he      is confident that he will not be unfair and unjust, and that he will be able      to give them their rights. 
     If he is afraid that any of this applies to him, then he      should limit himself to one, or to slaves that his right hand possesses,      because he is not obliged to divide his time equally when it comes to slave      women. 
     “That”, i.e., limiting yourself to one or to what your right      hand possesses (slave women) 
     “is nearer to prevent you from doing injustice” i.e.,      being unfair or unjust. 
     Limiting it to one applies in the case where a person fears      he may be unjust or unfair, and may fail to do what is required, so he      should err on the side of caution and not put himself in that position. 
     Tafseer al-Sa’di (p. 163). 
     It was narrated from Abu Hurayrah (may Allaah be pleased with      him) that the Prophet  (peace and blessings of Allaah be upon him) said:      “Whoever has two wives and favours one of them over the other, will come on      the Day of Resurrection with one of his sides leaning.” Narrated by      al-Tirmidhi (1141), Abu Dawood (2133), al-Nasaa’i (3942) and Ibn Majaah      (1969). Classed as saheeh by al-Albaani in Saheeh al-Targheeb      wa’l-Tarheeb (no. 1949). 
     Shaykh al-Mubaarakfoori (may Allaah have mercy on him) said: 
     Al-Teebi said in his commentary on the words “with one of his      sides leaning”, i.e., tilting. And it was said that this will be in such a      way that all the people on the Day of Resurrection will see him, so this      will increase his punishment. 
     Tuhfat al-Ahwadhi (4/248). 
     If a wife sees that her husband is favouring her co-wife at      her expense, or is being unjust to her with regard to her rights, she should      hasten to advise her husband in the way that is best, and remind him of what      Allaah has enjoined of justice, and what Allaah has forbidden of injustice.      She should also hasten to advise her co-wife not to accept this injustice,      and not to take anything that is not rightfully hers. Perhaps Allaah will      guide him to be just and to give each one her due rights. 
     Secondly: 
     One aspect of justice between co-wives is for the husband to      draw lots if he wants to travel with one wife and not the other(s). This is      what the Prophet  (peace and blessings of Allaah be upon him) did with      his wives.  
     It was narrated that ‘Aa’ishah (may Allaah be pleased with      her) said: When the Messenger of Allaah  (peace and blessings of Allaah      be upon him) wanted to go out on a journey, he would cast lots between his      wives and the one whose name was drawn, he would take her with him.
     Narrated by al-Bukhaari (2454) and Muslim (2770). 
     Al-Nawawi (may Allaah have mercy on him) said: This shows      that if a man wants to travel with one of his wives, he should cast lots      between them. In our view this casting lots is obligatory. 
     Sharh Muslim (15/210). 
     Ibn Hazm (may Allaah have mercy on him) said: 
     It is not permissible for him to choose one of his wives to      travel with him except by drawing lots. 
     Al-Muhalla (9/212). 
     Something similar was said by al-Shawkaani (may Allaah have      mercy on him) in al-Sayl al-Jiraar (2/304). 
     When he comes back from his trip, he should not count the      period of his trip for the wife who travelled with him as the result of      drawing lots.  
     ‘Abd al-Barr (may Allaah have mercy on him) said: 
     When he comes back from his journey, he should resume the      division of his time among them, and he should not count the days of the one      with whom he travelled. The hardship that the wife who accompanied him went      through as the result of travelling is in return for the time she got to      spend with him. 
     Al-Tamheed (19/266). 
     Thirdly: 
     If it is assumed that one of his wives was not able to travel      with him, it is pointless to include her in drawing lots, when she is unable      to travel with him. In that case, lots should be drawn among those whose      circumstances allow them to travel, and lots should not be drawn between      those who are able and those who are not. But this is based on the      assumption that this is the truth and not just an illusion or based on      mistreatment of her, such as if she is sick or she has children and cannot      leave them without someone to look after them, or she is not allowed to      travel, and other such reasons, and it is not because he wants the other      wife to travel with him and not the first one. Otherwise he is being      unjust. 
     In this case he has to try to please both wives, even if it      means making it up to the one who is not travelling by spending extra time      with her when he comes back from his trip. 
     Al-Haafiz Ibn Hajar (may Allaah have mercy on him) said: 
     Al-Qurtubi said: That varies according to women’s situations,      and the prescription of drawing lots applies only if their situations are      the same, lest one of them go out with him without a reason to make him take      her and not the other(s). 
     Fath al-Baari (9/311). 
     Dr. Ahmad al-Rayyaan said: 
     If the wives’ situations are the same in all aspects, then      drawing lots is a must. But if his wives differ in that, there is nothing      wrong with choosing, so long as he pays attention to the principles of not      favouring one of them and not aiming to cause harm. 
     Ta’addud al-Zawjaat (p. 71). 
     We do not know of any site that deals specifically with      issues of plural marriage. You can look at our site, and at other      trustworthy fatwa sites which deal with a lot of questions about plural      marriage. 
     We have compiled a separate section on our site dealing with      issues and rulings on plural marriage, and you can find it at this link: