Will there be sex in Heaven?

My hunch is that the answer is 'no' and there are two reasons for my conclusion.  

First, Jesus was once tested by a Sadducee (who probably didn't even believe in Heaven!), who asked him to which husband a woman that had been married seven times in her lifetime would be together with in Heaven. Jesus gave this answer: "For in the resurrection, they neither marry nor are given in marriage, but are like angels in Heaven." (Matthew 22:29-30).

Secondly, there appears may be an end to further procreation once 'the full number of Gentiles have come into the Kingdom of God.  (Romans 11:25)

Ultimately, we don't know one way or the other.

This may sound a bit disappointing to some. The potential absence of sex in Heaven shouldn't be construed as a stance against sex in the Bible. In fact, the Bible is quite positive about it (the whole book of the Song of Solomon dances with it, for example); the reason is that sex in marriage itself is a glimpse of the intimacy we'll have with God eternally. In that vein, throughout the Old and New Testaments, God describes himself as our husband.  Whether or not sex persists in Heaven, intimacy with God will occupy our attention and satisfy our desires at a level far above and beyond the best sexual experience on Earth.  

The apostle Paul writes this in 1 Corinthians 2:9 "No eye has seen, no ear has heard, no mind has conceived what God has prepared for those who love him." 

God never has less for those that love Him!