(It has been narrated) upon the authority of Aaisha - may Allah be pleased with her - that "The Messenger kissed one of his wives then he went out to prayer and didnt make wudhu" (Abu Daawood, An-Nasaa'ee and others).
In this hadeeth is a clarification of the ruling concerning touching and kissing a woman and whether or not that breaks the wudhu.
The scholars - may Allah have mercy upon them - differed concerning this. From them there were those who held that touching a woman breaks the wudhu in every circumstance. And from them were those who held that if he kisses her with desire then it breaks his wudhu and if not then his wudhu remains intact. Still from them are those who hold that the wudhu is never broken by that and this position is the strongest.
That is that if a man kisses his wife or touches her hand or hugs her, doesn't ejaculate and doesn't break his wudhu (by other means) then neither he nor his wife breaks wudhu. That is because the origin is that the wudhu remains intact until we have proof that it has been broken, and there isn't a proof in the Book of Allah or in the Sunnah of the Messenger of Allah that indicates that touching a woman breaks the wudhu.
On that basis touching a woman even without a barrier (i.e. clothing etc) even with desire, kissing her and hugging her all of that does not break the wudhu. And Allah knows best.