Why doesn't the Bible tell us that Jesus was a virgin?

The most common denomination that believes Mary is the eternal virgin is Catholicism. As noted here:

Patrology, 1:120–1

The principal aim of the whole writing [Protoevangelium of James] is to prove the perpetual and inviolate virginity of Mary before, in, and after the birth of Christ

However it is not universally accepted as fact. For instance, to consummate a marriage a woman's virginity was lost. The only exceptions would be if the woman was too young or the man too old. I have read stories about Joesph begin too old - which explains why he is not mentioned later in the Bible. I've also read stories were Mary may have been too young. But either way, it's pretty safe to assume (unless you share of the Catholic traditions) that the marriage was consummated at some point, potentially after the birth of Jesus.

One large debate is that of the translation / editing of the Bible. Was Mary a virgin or a young woman. Someone more familiar with biblical hermeneutics may be able to expand on this more than I can here. However, the quest is:

Isa 7:14 NIV

Therefore the Lord himself will give you[a] a sign: The virgin[b] will conceive and give birth to a son, and[c] will call him Immanuel.[d]

Footnotes:

Isaiah 7:14 The Hebrew is plural.

Isaiah 7:14 Or young woman

Isaiah 7:14 Masoretic Text; Dead Sea Scrolls son, and he or son, and they

Isaiah 7:14 Immanuel means God with us.

Here you can see that it is possible that Mary was a young woman which would also explain the lack of consummation right after the marriage. It is further explored here and resulting in American Catholic Bishops changing Mary from a virgin to a young woman.

John Allen, with the National Catholic Reporter in Rome

Their point in translating this reference to Mary as a 'young woman' rather than a 'virgin' is that the original Greek word doesn't mean what we in contemporary English mean by a 'virgin.' It simply means a young woman

So why doesn't the Bible mention Jesus virginity state? Probably because it wasn't important. For instance, they don't mention the virginity of most of the people in the bible. Was Abel a virgin? Why would we care if his was or wasn't? There are stories that say that Jesus was married, but they were not added to the canon. The stories have made Dan Brown extremely wealthy. Please consider reading this.

One of the books not accepted in the canon was The Gospel of Philip which states:

section 59

There were three who always walked with the Lord: Mary his mother and her sister and Magdalene, the one who was called his companion

and

section 63

And the companion of the Savior is Mary Magdalene. But Christ loved her more than all the disciples and used to kiss her often on her mouth[sic]. The rest of the disciples were offended by it and expressed disapproval. They said to him, ‘Why do you love her more than all of us?’ The Savior answered and said to them, ‘Why do I not love you like her?’ When a blind man and one who sees are both together in darkness, they are no different from one another. Then the light comes, then he who sees will see the light, and he who is blind will remain in darkness

John 21:25:

Jesus did many other things as well. If every one of them were written down, I suppose that even the whole world would not have room for the books that would be written.

If "the whole world" would not have space for all the things He did do, it is unlikely to have space for all the things he didn't.

The Bible does emphatically state that Jesus was without sin.

For we do not have a high priest who is unable to sympathize with our weaknesses, but one who in every respect has been tempted as we are, yet without sin. Hebrews 4:15 ESV

Since Jesus was never reported to have been married in the Bible, a sexual relationship would have been a sin. Since Jesus is and was and forever will be sinless, we can know for certain that Jesus was also a virgin.

This is implicit rather than explicit, but no less certain.