This is a historical question and so we can only go on the evidence we have. The fact is there is zero evidence he was married, zero evidence he had any kind of sexual relationship and zero evidence of any children fathered by him.
People have come up with flawed, kooky theories about Jesus being married, all of which are based on misreadings, misunderstandings or wild fantasy. A reference in the Second to Third Century Gospel of Philip to Jesus kissing Mary Magdalene “on her xxx” (the manuscript has a hole at the key point) is taken as evidence they were married.
This ignores many things: (i) the text is a very late one, of a highly symbolic nature and not used by historians for historical evidence, (ii) the text was written by Gnostics who emphasised the spiritual nature of Jesus, believed he wasn’t human at all and downplayed any physical aspects to life, (iii) the exchange of a kiss symbolised the exchange of mystical knowledge and did not have modern, romantic connotations at all, which is why another Gnostic text of the same period had Jesus kissing and embracing his brother James and calling him “my beloved”.
Other arguments have tried to project much later rules about how all Jewish rabbis have to marry onto Jesus’ time, which simply doesn’t work. Or they have claimed that celibacy was unheard of amongst Jews in Jesus’ time, which is simply completely wrong. There are multiple examples of celibacy amongst holy men in Jesus’ time, the most prominent being the Essene sect. Jesus’ only comment on marriage in the gospels praises celibacy and when Paul (also celibate) wants to hold up an example of good marriage he turns to the example of Peter and the other disciples, not Jesus.
All the evidence, therefore, indicates that Jesus was another First Century celibate holy man. Given that he seems to think the world as we know it was about to end, this makes sense.
That he had no descendants is also fairly clear from the evidence. The leadership of his sect’s community in Jerusalem passed to his brother James, and then after James’ execution to his nephew or cousin Simeon. This was in 62 AD, by which time any son of Jesus would have been an adult, yet while the leadership stayed in his family, it did not pass to any son and no daughter is mentioned either. Not long afterwards the gospel writers wrote accounts of his crucifixion drawing on Isaiah 53 and trying to make out that this passage predicts things about Jesus and his death. Some elements in that passage are left out of their accounts though, because they don’t fit Jesus at all. This includes Isaiah 53:10 “he will see his offspring and prolong his days”. If Jesus had any offspring to see, that would have been brought into the gospel story to “fulfill” this prophecy.
Finally, in the reign of the Emperor Domitian some men who were from Galilee around Nazareth and who were said to be related to Jesus were questioned by the Romans for fear they may be rebels against Rome. They were released once they were found to be no more than harmless farmers, but not before they made it clear they were descendants of one of Jesus’ brothers. Jude, and not of Jesus himself.
To sum up, there is zero evidence he married, no evidence he had children and any claims to the contrary are pseudo historical fantasies based on misreadings of the evidence or, in most cases, the desire to sell kooky books and make money.