Does Touching the Husband’s Penis Invalidate Wudu?
Question

What is the ruling if a woman touches her husband’s penis; does it invalidate her Wudu? Does it invalidate her Wudu whether she touches it with or without a barrier, with or without desire? Does greeting the wife with Salam and touching her invalidate Wudu, even if it is without desire, and if it is with desire, does it invalidate it? Does kissing invalidate the Wudu of the wife and husband, or does it invalidate the Wudu of the one who kisses the other?
Praise be to Allah.Does touching your penis break Wudu?
The scholars (may Allah have mercy on them) differed as to whether touching the penis invalidates Wudu or not . The most correct view is that if the touching is done with desire, it invalidates Wudu. 
Does touching the husband’s penis invalidate Wudu?
If a woman touches her husband’s penis with desire, it invalidates her Wudu, but if it is without desire, then it does not invalidate it. 
`Ulaysh (may Allah have mercy on him) said in Minah Al-Jalil Sharh Mukhtasar Khalil (1/113): “The ruling on touching the penis of another person depends on whether it was done deliberately or whether accompanied by desire.”
Does touching the husband’s penis with a barrier break Wudu?
If we say that it does invalidate Wudu, that is on condition that there is no barrier. This is the view of the majority of scholars. So if a woman touches her husband’s penis with a barrier, her Wudu is not invalidated, even if it is with desire. Abu Hurayrah (may Allah be pleased with him) narrated that the Prophet (blessings and peace of Allah be upon him) said: “If one of you touches his private parts, with no barrier in between, then let him do Wudu.” (Narrated by Ash-Shafi`i in his Musnad, 1/12; classed as authentic by Shaykh Al-Albani in Sahih Al-Jami`) 
(Also see: Hashiyat Ad-Dusuqi, 1/120; Mughni Al-Muhtaj, 1/1.2; Matalib Uli An-Nuha, 1/143)
Does touching or kissing the spouse invalidate Wudu?
If a man shakes hands with his wife or kisses her , or she kisses him, that does not invalidate the Wudu of either of them, even if it is done with desire, so long as nothing is emitted. `Aishah (may Allah be pleased with her) narrated  the Prophet (blessings and peace of Allah be upon him) kissed one of his wives, then went out to pray and did not do Wudu. (Narrated by At-Tirmidhi, 86; An-Nasa’i, 1/104; Ibn Majah, 502)
Shaykh `Abd Al-`Aziz ibn Baz (may Allah have mercy on him) said: 
“… The correct scholarly view is that it does not invalidate Wudu at all. If a man touches his wife or kisses her, it does not invalidate his Wudu according to the most correct opinion, because the Messenger (blessings and peace of Allah be upon him) kissed one of his wives, then he prayed and did not do Wudu. Also, the basic principle is that Wudu and purity remain intact, and it is not permissible to say that it has been invalidated by something unless there is proof to that effect, with no counterproof. In this case there is no proof to indicate that Wudu is invalidated by touching one’s wife at all.” (Majmu` Al-Fatawa, 17/219)
For more details, please see the following answers: 8531 , 82521 , and 191686  
And Allah knows best.