✅ Answer: Please refer to the following narrations:

1⃣عَنْ زُرَارَةَ عَنْ أَبِي جَعْفَرٍ أَنَّهُ قَالَ:

لَا تُعَادُ الصَّلَاةُ إِلَّا مِنْ خَمْسَةٍ الطَّهُورِ وَ الْوَقْتِ وَ الْقِبْلَةِ وَ الرُّكُوعِ وَ السُّجُود

📚 Al-Faqih, vol. 1, p. 339

Imam Baqir (AS) said: Prayer is not to be repeated except in five cases: purification (wudu, ghusl, or tayammum), time, qiblah, ruku, and sujud.

2⃣عَنِ الْحَلَبِيِّ قَالَ سُئِلَ أَبُو عَبْداللَّهِ عَنْ رَجُلٍ أَجْنَبَ فِي شَهْرِ رَمَضَانَ فَنَسِيَ أَنْ يَغْتَسِلَ حَتَّى خَرَجَ شَهْرُ رَمَضَانَ قَالَ عَلَيْهِ أَنْ يَقْضِيَ الصَّلَاةَ وَ الصِّيَامَ

📚 Al-Tahdhib, vol. 4, p. 311

Halabi says: I asked Imam Sadiq (AS) about someone who becomes ritually impure (janabah) during Ramadan and forgets to perform the ghusl until Ramadan ends. The Imam replied: He must make up the missed prayers and fasts!

3⃣قَالَ الصَّدُوقُ وَ رُوِيَ فِي خَبَرٍ آخَرَ أَنَّ مَنْ جَامَعَ فِي أَوَّلِ شَهْرِ رَمَضَان ثُمَّ نَسِيَ الْغُسْلَ حَتَّى خَرَجَ شَهْرُ رَمَضَان أَنَّ عَلَيْهِ أَنْ يَغْتَسِلَ وَ يَقْضِيَ صَلَاتَهُ وَ صَوْمَهُ إِلَّا أَنْ يَكُونَ قَدِ اغْتَسَلَ لِلْجُمُعَةِ- فَإِنَّهُ يَقْضِي صَلَاتَهُ وَ صِيَامَهُ إِلَى ذَلِكَ الْيَوْمِ وَ لَا يَقْضِي مَا بَعْدَ ذَلِكَ

📚 Al-Faqih, vol. 2, p. 119

Shaykh Saduq says: In another narration, it is reported that if someone engages in sexual intercourse at the beginning of Ramadan and then forgets to perform the ghusl until Ramadan ends, he must perform the ghusl and make up his prayers and fasts, unless he has performed the Friday ghusl, in which case he only needs to make up the prayers and fasts up to that day and not after it.

3⃣ From Ali bin Mahziyar in a narration: If a man’s clothes are impure, he does not have to repeat the prayer except for what is within its time. If he is in a state of janabah or has prayed without wudu, he must repeat the obligatory prayers that he missed, because clothing is different from the body. So, act according to that, insha’Allah.

📚 Al-Tahdhib, vol. 1, p. 426

In a narration, Ali bin Mahziyar reported that Imam (Jawaad or Imam Hadi) (AS) wrote to him in response to a question: A person does not have to repeat the prayer if his clothes are impure, except for what is within its time. However, if he is in a state of janabah or prays without wudu, he must repeat the obligatory prayers that he missed, because clothing is different from the body. So, insha’Allah, act accordingly.

4⃣عَنْ عَبْدالصَّمَدِ بْنِ بَشِیرٍ عَنْ أَبِی عَبْداللَّه فِی حَدِیثٍ مَنْ أَحْرَمَ فِی قَمِیصِهِ إِلَی أَنْ قَالَ أَیُّ رَجُلٍ رَکِبَ أَمْراً بِجَهَالَةٍ فَلَا شَیْءَ عَلَیْهِ.

📚 Al-Tahdhib, vol. 5, p. 72

Imam Sadiq (AS) said in a narration: Anyone who does something out of ignorance is not responsible for it!

5⃣عَنْ مُحَمَّدِ بْنِ إِسْمَاعِیلَ یَعْنِی ابْنَ بَزِیعٍ قَالَ: سَأَلْتُ الرِّضَا عَنِ الرَّجُلِ یُجَامِعُ الْمَرْأَةَ قَرِیباً مِنَ الْفَرْجِ فَلَا یُنْزِلَانِ مَتَی یَجِبُ الْغُسْلُ فَقَالَ إِذَا الْتَقَی الْخِتَانَانِ فَقَدْ وَجَبَ الْغُسْلُ فَقُلْتُ الْتِقَاءُ الْخِتَانَیْنِ هُوَ غَیْبُوبَةُ الْحَشَفَةِ قَالَ نَعَم

📚 Al-Kafi, vol. 3, p. 46

Ibn Bazi' says: I asked Imam Reza (AS) about a man who has intercourse with a woman without ejaculation. When is ghusl obligatory on him? The Imam replied: When the two circumcised parts meet, ghusl is certainly obligatory! I asked: Does this mean when the glans and head of the male organ are concealed inside? The Imam said: Yes!

✅ Based on the above narrations and others, if intercourse occurs with the tip of the male organ being concealed inside, both become ritually impure and must perform ghusl, and the fast is invalidated, even if neither experiences ejaculation. They are obligated to make up the fast and pay the expiation.

✅ However, if they were completely ignorant and performed this act thinking that intercourse without ejaculation would not invalidate the fast, based on narration 4⃣, they are not responsible for the expiation and only need to make up the fasts they missed in this condition without performing the ghusl. They also need to make up the prayers until they have performed the ghusl.

Therefore, from the time this act is committed until the ghusl is performed, they must make up all their prayers and fasts. The expiation is waived only due to their ignorance of the fact that intercourse without ejaculation breaks the fast, and if they were aware, they would be obligated to pay the expiation as well.