His wife is accusing himof harassing her sister and he said to her: If I touch your sister then our marriage is invalid. Then he touched her again with desire.

Dought & clear, - My wife and I where having an argument. She was
telling me that she does not like the way I talk to her sister and
going on about it etc. I told her "you knowif I even touch suraya (my
wifes sister) nikah breaks". I am certain that i had no intention of
any talaq. When I made that statement"you know if I even touch suraya
(my wifes sister) nikah breaks" I was like just lying/making up for it
toseem that that is the islamic ruling. I just told her that to give
her like assurance that I wont dowrong actions with her sister. After
some time about couple of months afterwards I touched my wifes sister
with lust. Then after some months I may have touched her with lust
again. Now I get waswasa that when Imade that statement I had
intention of talaq. I am 99.9% sure that I hadno intention of talaq
butthis waswasa is making me feel as though I had intention. The only
intention I may have hadwas not to touch my sister in law and only to
give my wife assurance that Im not allowed to do wrong with her
sisterand that I won't do wrong with her sister . I am certain I had
NO intention of talaq. Is there any talaq in this situation? If there
is talaq how many talaqs take place?
Praise be to Allah.
Firstly:
You should realise that what has happened of you touching your
wife'ssister with desire is something that is undoubtedly haraam. It
comes under the heading of zina (adultery) of the hand, of which the
Messenger of Allah (blessings and peace of Allah be upon him) spoke.
Zina is not only zina of the private part; rather there is also zina
of the hand, which is haraam touching, and zina of the eye, which is
haraam looking, even though it is zina of the private part that incurs
the hadd punishment. After this, how can you claim that there is no
reason for suspicion andthat your wife has no right to be suspicious
about you. What you aredoing is very suspicious and is indicative of
bad intentions and a bad attitude.
It says in the hadeeth narrated by Abu Hurayrah from the Prophet
(blessings and peace of Allah be upon him) that he said: "Allah has
decreed for the son of Adam his share of zina, which he will
inevitably get. The zina of the eyes is looking and the zina of the
tongue is speaking. The heart wishes and hopes, and the private part
confirms that or denies it."
Narrated by al-Bukhaari,5889; Muslim, 2657.
According to a version narrated by Muslim: "Thezina of the eyes is
looking, the zina of the ears is listening, the zinaof the tongue is
speaking, the zina of thehands is touching, and the zina of the foot
is walking. The heart longsand wishes, and the private part confirms
that or denies it."
The Messenger of Allah (blessings and peace of Allah be upon him)
warned against touching a non-mahram woman and said: "If one of you
were to be stabbed in the head with an iron needle, thatwould be
better for him than touching a woman who is not permissible for him."
Narrated by at-Tabaraani from the hadeeth of Ma'qil ibn Yasaar;
classed as saheehby al-Albaani in Saheeh al-Jaami', no. 5045.
If this is a sin and crime in the case of any woman, and means that
you cannot be trusted, then how about if it involves your wife's
sister, who is haraam to you so long as her sister is your wife?
What you must do is ask Allah, may He be exalted,to forgive you for
this sin and repent to Him; you must also resolve not to do that again
and to block all ways that may lead to fitnah or temptation with this
woman. So do not be alone with her, and do not be with her in any
place or in any situation that could lead you to goback to what you
had been doing.
Moreover, there is no need for you to speak to her, with or without
desire; if there is any reason for you to speak, her sister – namely
your wife – can take care of it.
Secondly:
With regard to your saying to your wife, "If I touch your sister then
our marriage is invalid ('nikah breaks')," this is a metaphor for
divorce. In the case of metaphors, divorce doesnot take place unless
there was the intention of divorce, as we have explained in fatwa no.
120947
So long as you did not intend divorce thereby –as you say in your
question, trusting what you said – then divorce has not taken place.
And Allah knows best.