He wants his wife to break her fast and make it up later for no reason

Firstly: 

Saying “fate decreed” is not correct, because the One Who
wills and decrees is Allaah, the One, the Subduer, may He be glorified and
exalted. We have already discussed this in the answer to question no.
8621. 

Secondly: 

Breaking the fast in Ramadaan for no reason is a major sin,
and the one who does it is a faasiq (rebellious evildoer) who has to
repent to Allaah from this major sin. 

It was narrated that the Prophet (peace and blessings of
Allaah be upon him) issued a stern warning to the one who breaks the fast in
Ramadaan for no reason. 

Al-Haakim narrated that the Prophet (peace and blessings
of Allaah be upon him) saw the punishment of the one who breaks the fast in
Ramadaan for no reason, He said: “We saw some people hung up by their
Achilles tendons, with the corners of their mouths torn and pouring with
blood. I said, ‘Who are these?’ He said: ‘These are the people who broke
their fast before it was permissible for them to do so.’” 

Classed as saheeh by al-Albaani in al-Silsilah al-Saheehah,
3951. 

Based on this, this
husband has to fear Allaah and not take the matter of fasting lightly, for
it is a serious matter. 

You should not obey him in this matter, for there is no
obedience to any created being if it involves disobedience towards the
Creator. 

Breaking the fast in Ramadaan and making it up later on is
only prescribed for those who break the fast for a legitimate reason such as
sickness, traveling etc. But if a Muslim breaks the fast in Ramadaan for no
reason, he exposes himself to the wrath and punishment of Allaah. We ask
Allaah to keep us safe and sound. 

See also question no.
38747. 

Thirdly: 

Intercourse is one of the things that break the fast, and it
is one of the most serious of such things in terms of sin. Hence kafaarah
(expiation) must be offered for it. 

Shaykh Ibn ‘Uthaymeen (may Allaah have mercy on him) said in
Fataawa al-Siyaam (p. 337): 

The one who has
intercourse during the day in Ramadaan when he is fasting and is not
traveling has to offer a burdensome expiation, which is freeing a slave; if
he cannot do that then he must fast for two consecutive months; and if he
cannot do that then he must feed sixty poor persons. The same applies to the
woman if she was willing, but if she was forced then she does not have to do
anything. If they were traveling then there is no sin on them and they do
not have to offer any expiation, and they do not have to refrain from eating
for the rest of the day, but they do have to make up that day, because
fasting is not obligatory for them (as they are traveling). If a person had
intercourse when he was fasting in his own country and was one of those who
are obliged to fast, five things result from that: 

1-    
It is a sin

2-    
The fast is invalidated

3-    
He has to refrain from eating
etc for the rest of the day

4-    
He has to make up the fast

5-    
He has to offer expiation. 

The evidence for that is the hadeeth of Abu Hurayrah (may
Allaah be pleased with him) who said: Whilst we were sitting with the
Prophet (peace and blessings of Allaah be upon him), a man came and
said, “O Messenger of Allaah, I am doomed!” He said: “What is the matter
with you?” He said, “I had intercourse with my wife when I was fasting.” The
Messenger of Allaah (peace and blessings of Allaah be upon him) said:
“Do you have a slave whom you can set free?” He said, “No.” He said: “Can
you fast for two consecutive months?” He said, “No.” He said, “Can you
afford to feed sixty poor persons?” He said, “No.” The Prophet (peace
and blessings of Allaah be upon him) fell silent for a while, and whilst we
were like that, a basket of dates was brought to the Prophet (peace and
blessings of Allaah be upon him). He said: “Where is the one who was
asking?’ He said, “Here I am.” He said: ‘Take this and give it in charity.”
The man said: “To someone poorer than me? O Messenger of Allaah, there is no
family between the two lava fields (i.e., in Madeenah) poorer than mine.”
The Prophet (peace and blessings of Allaah be upon him) smiled until
his eyeteeth became visible, then he said: “Feed it to your family.”
Narrated by al-Bukhaari, 1936; Muslim, 1111. 

If this man cannot fast or feed the poor, then the obligation
to offer expiation is waived, because Allaah does not burden any soul beyond
its scope, and there is no obligation if one is unable to do it. It makes no
difference whether there was any ejaculation or not, so long as intercourse
has taken place. This is unlike the case when ejaculation takes place
without intercourse, for which no expiation is due, rather this is a sin,
and the person must refrain from eating etc for the rest of the day, and
make the day up. 

He was also asked about a man who forces his wife to have
intercourse during the day in Ramadaan, and replied: 

It is haraam for her to obey her husband or to allow him to
do that in this case, because she is observing an obligatory fast. She has
to resist him as much as possible. It is haraam for her husband to have
intercourse with her in this case, but if she cannot stop him then there is
no sin on her, and she does not have to make up the day or offer any
expiation, because she was forced to do it. 

Fataawa al-Siyaam, p. 339.