Sometimes the answers in the Bible are less easy to understand than they are on subjects which are directly addressed.
You have seen from the previous answers What Jesus said about the Angels in Heaven, not marrying, So first of all is there anything which elaborates on this in the Bible, and the answer is yes.
All Scripture is quoted from the King James translation, unless otherwise noted.
First of all we must determine what Marriage is in the eyes of God. Our first clues come from Genesis:
Genesis 1:21 and 22 And God created great whales, and every living creature that moveth, which the waters brought forth abundantly, after their kind, and every winged fowl after his kind: and God saw that it was good. And God blessed them, saying, Be fruitful, and multiply, and fill the waters in the seas, and let fowl multiply in the earth.
Genesis 1:24 and 25 And God said, Let the earth bring forth the living creature after his kind, cattle, and creeping thing, and beast of the earth after his kind: and it was so.
And God made the beast of the earth after his kind, and cattle after their kind, and every thing that creepeth upon the earth after his kind: and God saw that it was good.
With the animals God decreed that that they multiply, but he did not give any commands as to how that was to be accomplished, but with man things are different.
Genesis 1:26 and 27 And God said, Let us make man in our image, after our likeness: and let them have dominion over the fish of the sea, and over the fowl of the air, and over the cattle, and over all the earth, and over every creeping thing that creepeth upon the earth. So God created man in his own image, in the image of God created he him; male and female created he them.
As we see here God created man completely different from the animals, they were not made in his image, and we see that God gave man dominion over the animals. So in fact what God did was to make man as a mini god to the animals. This would appear to be a part of creating man in God's image, since as God is sovereign over man so man is sovereign over the animals.
So lets take a longer look at what God meant in Genesis 1:26 and 27. So God created them in his own image male and female, but God is tripartite to most Protestant Christians, and he only created them in duality that is male and female. So lets take a look at what the Trinity consists of, that being the Father, the Holy Spirit and the begotten son. So since we are created in the image of God where is our third part? Just as the son is the third part of the Trinity, so our children are the third part of our family. That is why God decreed that man should:
Genesis 1:28 And God blessed them, and God said unto them, Be fruitful, and multiply, and replenish the earth, and subdue it: and have dominion over the fish of the sea, and over the fowl of the air, and over every living thing that moveth upon the earth.
From this I surmise that God intended that man and woman come together and produce offspring to continue his image on the Earth, and the children should keep that image in perpetuity until the end. In my humble opinion preservation of that image is why God said:
Deuteronomy 5:16 Honour thy father and thy mother, as the LORD thy God hath commanded thee; that thy days may be prolonged, and that it may go well with thee, in the land which the LORD thy God giveth thee.
Genesis 2:24 Therefore shall a man leave his father and his mother, and shall cleave unto his wife: and they shall be one flesh.
Genesis 2:23 And Adam said, This is now bone of my bones, and flesh of my flesh: she shall be called Woman, because she was taken out of Man.
If woman was bone of his bone and flesh of his flesh because she was taken out of man, would not children also be since they were taken; not only of her, but of him also. And should all three not then be one as is the Trinity.
Satan knows that if he can get rid of that family image of God he can materially hamper God's plan. That is why I personally disagree with the attack on traditional marriage, and part of my reason for objecting to Abortion.
Now that we have defined what God considers marriage to be, lets look at whether or not we will be physically sexual when we go to Heaven.
As we see from the Scriptures above God made the man and woman as part of his image, what then was the reason he made them different in physical form. That reason appears to be for procreation purposes, and that will not be needed in Heaven since all things will be settled, and Heaven will not need procreation since it will as God wants it to be.
Revelation 10:7 But in the days of the voice of the seventh angel, when he shall begin to sound, the mystery of God should be finished, as he hath declared to his servants the prophets.
The mystery of God is finished, and to me that says that God's plans for his creation is finished. That has a lot of meaning to it. God has a specific reason for all that he does, and when that reason is accomplished He will no longer continue that plan. Since it is apparent that God had procreation in mind at creation, when that has been completed to his satisfaction; it is also apparent that he will no longer support that part of his plan. Beyond that we as Christians will have a specific task to perform in Heaven, which from my understanding is to worship him night and day. Sex as we know it would interfere with that task and so it makes sense to me that it will be discontinued.
In Heaven as opposed to here on Earth we will only be interested in God's edification and not our own.
That is my interpretation of the Scriptures, you may or may not agree. At any rate I hope this will give you a basis for future study.