Individual choice. Asexual, heterosexual, different orientation, all OK. For the heterosexual majority in Hinduism, sex is 'dharma', one of the four things that a person should engage in (Purushartha). Did I not promise to my wife that we will seek pleasure in each other?
Dhruva Dhyaanam Darshanam Va (meditating on the Pole star and the Arundhati star)
The Pole Star is stationary and fixed in its position, likewise the couple is expected to be steadfast and firm in fulfilling their vows and responsibilities.
The bride:
Just as the star Arundhati (Star Alcor in Great Bear constellation) is attached to the star Vasishtha (Star Mizar), so may I be ever firmly attached to my husband!
Placing his hand upon the bride’s forehead, the bridegroom:
As the heavens are permanently stable, as the earth is permanently stable, as these mountains are permanently stable, and as the entire universe is permanent stable, so may my wife be permanently settled in our family! - Rig Veda X.173.4
(Addressing the bride): You are the Pole star; I see in you stability and firmness. May you ever be steadfast in your affection for me. The great God has united you with me. May you live with me, blessed with children, for a hundred years!
Marriage:
Vivaah - Wikipedia