The scriptures are divided on this. Viṣṇu Purāṇa says the husband shouldn't approach an unwilling wife while Bṛhadāraṇyaka Upaniṣad suggests he should do whatever is necessary to pass on his genes.
Rules for Sexual Activity, Vishnu Purāṇa 3.11:
111. In proper time, under the influence of an auspicious planet and in
an auspicious moment or on even nights (tithis) one should have sex
with his own wife.
112 – 113. One should not approach a woman who is unbathed, sick,
menstruating, unwilling, angry, un-recommended, pregnant, unskilled
(adaksinam), in love with another (anya-kamam), lacking in libido
(akamam) nor committed to another (anya-yoshitam), nor if she is
hungry or over-fed. He too should also be free from all these
imperfections.
114. When engaging in sexual intercourse (vyavayam) one should have
taken a bath, be adorned with a garland and perfumes, and be in an
aroused and affectionate mood, not disturbed by anxiety.
(The Hindu Sacrament of Marriage by Pandit Sri Rama Ramanuja Achari (srimatham.com)
From here, the Sanskrit word for 'unwilling' is nāniṣṭāṃ:
ṛtāv upagamaḥ śastaḥ svapatnyām avanīpate /
punnāmarkṣe śubhe kāle jyeṣṭhayugmāsu rātriṣu //
nāsnātāṃ tu striyaṃ gacchen nāturāṃ na rajasvalām /
nāniṣṭāṃ na prakupitāṃ nāpraśastāṃ na garbhiṇīm //
nādakṣiṇāṃ nānyakāmāṃ nākāmāṃ nānyayoṣitam /
kṣutkṣāmām atibhuktāṃ vā svayaṃ caibhir guṇair yutaḥ //
snātaḥ sraggandhadhṛk prītaḥ nādhmātaḥ kṣudhito 'pi vā /
sakāmaḥ sānurāgaś ca vyavāyaṃ puruṣo vrajet //
Bṛhadāraṇyaka Upaniṣad
Chapter VI - Section IV - Conception and Birth as Religious Rites
The earth is the essence of all these beings, water the essence of the earth, herbs of water, flowers of herbs, fruits of flowers, man of
fruits, and the seed of man. [6.4.1]
Prajāpati thought, 'Well, let me make an abode for it,' and he created woman.
3-6. If man sees his reflection in water, he should recite the
following Mantra: '(May the gods grant) me lustre, manhood,
reputation, wealth and merits.' She (his wife) is indeed the goddess
of beauty among women. Therefore he should approach this handsome
woman and speak to her.
If she is not willing, he should buy her over; and if she is still unyielding, he should strike her with a stick or with the hand and
proceed, uttering the following Mantra, 'I take away your reputation,'
etc. She is then actually discredited. [6.4.7]
If she is willing, he should proceed, uttering the following Mantra: 'I transmit reputation into you,' and they both become
reputed.
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