The Mahabharata confirms that two males can have children together. That, by definition, is sexuality within two males, making it homosexuality.
that best of Brahmanas, Utanka heard of it. And Utanka who was possessed of great energy and immeasurable soul,
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And Utanka said,
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And it extends many yojanas in length and breadth and in that desert dwells a chief of the Danavas called Dhundhu by name. And Dhundhu is the son of Madhu and Kaitabha, and is fierce and terrible and possessed of great prowess. And endued with immeasurable energy, that Danava, O king, dwells under the ground, and, O king, it behoves you to retire into the woods, having first slain that Asura.
Madhu and Kaitabha are both male. This is confirmed later in the story by Vishnu.
Markandeya said,
...
Thus addressed by them the holy one spoke,
'You brave ones, I will accept a boon from you. There is a boon that I desire. Both of you are possessed of mighty energy. There is no male person like unto any of you. O you of unbaffled prowess, submit you to be slain by me. Even that is what I desire to accomplish for the good of the world.'
Also, Kaitabha's name does not make sense to be female and Madhu is confirmed to be male in the Hari Vamsha, which is part of the Mahabharata with a male epithet (Asuri is the female form of Asura according to the vedas https://en.wikipedia.org/wiki/Asura).
Vaishampayana said:—After the revolution of a thousand Yugas and the commencement of Satya-Yuga the quality of Tamas (disorganizing tendency) prevails. At this time the great Asura Madhu.
Also, Madhu and Kaitabha did not adopt Dhundhu, because in a rely to a question of its grandparent, Madhu and Kaitabha's father Vishnu is said to be their grandfather (Madhu and Kaitabha are pretty old, when incest laws did not really apply). Adopted relationships do not carry over to other relatives otherwise there is a contradiction with Arjuna and Subhadra's relationship.
"Yudhishthira said,
'O holy one, O you possessed of the wealth of asceticism, who was this Daitya of great energy? Whose son and whose grandson was he? I desire to know all this; O you possessed of the wealth of asceticism I never heard of this mighty Daitya before. I desire to know all this truly, O holy one, and with all particulars in detail, O you of great wisdom and ascetic wealth!'
"Markandeya said,
'O monarch, know everything as it happened, O ruler of men, as I narrate the particulars truly, O you of great wisdom! When the world became one broad expanse of water and creatures mobile and immobile were destroyed, when, O bull of the Bharata race, the entire creation came to its end.
He who is the Source and Creator of the Universe, viz., the Eternal and unfading Vishnu, He who is called by Munis crowned with ascetic success as the Supreme Lord of the Universe, that Being of great holiness, then lay in Yoga sleep on the wide hood of the Snake Sesha of immeasurable energy, and the Creator of the Universe, that highly-blessed and holy Hari, knowing no deterioration, lay on the hood of that Snake encircling the whole Earth and as the Deity lay asleep on that bed, a lotus, endued with great beauty and effulgence equal unto that of the Sun, sprang from his navel.
And from that lotus possessed of effulgence like unto the Sun’s, sprang the Grandsire Brahma, that lord of the worlds who is the four Vedas, who has four forms and four faces, who is invincible in consequence of his own energy and who is endued with mighty strength and great prowess and as the Lord Hari of wondrous frame, possessed of great lustre and decked with a crown and the Kaustubha gem and attired in purple silk, lay stretched for many a yojana on that excellent bed furnished by the hood of the snake itself extending far and wide, blazing, O king, in his beauty and the lustre of his own body like a thousand Suns concentrated in one mass.
He was beheld some time after by two Danavas of great prowess named Madhu and Kaitabha and beholding Hari (in that posture) and the Grandsire with eyes like lotus-leaves seated on that lotus, both Madhu and Kaitabha wandered much and they began to terrify and alarm Brahma of immeasurable prowess, and the illustrious Brahma alarmed by their continued exertions trembled on his seat, and at his trembling the stalk of the lotus on which he was seated began to tremble and when the lotus-stalk trembled, Kesava awoke.
And awakened from his slumber, Govinda beheld those Danavas of mighty energy, and beholding them the Deity said unto them,
'Welcome, you mighty ones! I am gratified with you! Therefore, I will grant you excellent boons!'
And thereupon both those proud and mighty Danavas, O king, laughingly replied unto Hrishikesa, saying,
'Ask boons of us, O Divine one! O you that art the Supreme Deity, we are disposed to grant you a boon. Indeed, we will grant you a boon! Therefore, ask you of us anything that comes to your mind.'
Thus addressed by them the holy one spoke,
'You brave ones, I will accept a boon from you. There is a boon that I desire. Both of you are possessed of mighty energy. There is no male person like unto any of you. O you of unbaffled prowess, submit you to be slain by me. Even that is what I desire to accomplish for the good of the world.'
Hearing these words of the Deity, both Madhu and Kaitabha said,
'We have never before spoken an untruth; no, not even in jest; what shall we say of other occasions! O you foremost of male Beings, know that we have ever been firm in truth and morality. In strength, in forms, in beauty, in virtue, in asceticism, in charity, in behaviour, in goodness, in self control, there is no one equal unto either of us.
A great danger, O Kesava, has approached us. Accomplish you, therefore, what you have said. No one can prevail over Time. But, O Lord, there is one thing that we desire to be done by you. O you best and foremost of all Deities, you must slay us at a spot that is absolutely uncovered.
And, O you of excellent eyes, we also desire to become your sons. This is the boon that we desire, know then, O chief of the gods! Let not that O Deity, be false which you had at first promised to us.'
The Holy One then replied unto them saying,
'Yes, I will do as you desire. Everything will be as you wish!'
No one else but Vishnu is mentioned in the answer who could be their grandfather. Thus, Madhu and Kaitabha did not adopt Dhundhu.
Thus, humans not being able to have two men have a child together is because of lack of technology and lack of Deva powers. Thus, any claim against homosexuality in general has to not be based around the ability to have children, which is the usual argument.
P.S. Technically you could argue they are identical twins and thus are
https://www.wisdomlib.org/hinduism/book/the-mahabharata-mohan/d/doc7481.html
https://www.wisdomlib.org/hinduism/book/harivamsha-purana-dutt/d/doc485697.html