All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad is His Slave and Messenger.
As long as the marriage bond is still intact, it is lawful for the husband to have intercourse with his wife. The fact that he intends to divorce her does not mean that he cannot enjoy her sexually as far as Sharee'ah is concerned. His saying to her "I hope you do not feel that I am using you" could have a positive effect on her and motivate her to fulfill her duties towards him, and this could cause him to keep the marriage and change his mind about divorce.
In any case, the husband should not divorce his wife without a legitimate reason or a prevalent general good. The scholars declared it disliked for a husband to divorce his wife without a valid reason. Some scholars even deemed it prohibited due to the harmful consequences of it.
Ibn Qudaamah said, explaining the legal status of the types of divorce, “The disliked divorce is to divorce without any need for it. Al-Qaadhi said, "There are two scholarly views on this. The first, it is prohibited because the husband wrongs himself and his wife and it constitutes denying both of them the benefits of marriage without real need; therefore, it is prohibited just like unjustifiably destroying wealth. Moreover, the Prophet said: 'There should be neither harm nor reciprocal harm.'"” [Al-Mughni]
For more benefit, please refer to Fatwa 87786.
Allaah Knows best.