This is silly.
First of all, sex is just one of many pleasures in life and far from one of the most enduring.
Second, the real source of pleasure in sex is the feeling of being loved and desired by someone and being able to fulfil that desire for them: an act of giving, that one knows is appreciated.
Third, interest in sex declines as one ages, implying it is an interest that is largely created and supported by the chemical hormones of the body, rather than anything fundamental in the mind.
Given the above, it seems likely that the pleasures of heaven, whatever they may be, won't have much to do with something as superficial and transitory as sex.
If heaven exists, it will be a state in which there are no more questions because we will know the answers.