Don't know their God, He never told me that.
People who want to agree with their God should simply refrain from homosexuality. There's no religious litmus test to adopt.
Here's one particular god - do you condemn this god?
Genesis 1:28
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.
Genesis 9:1
1 And God blessed Noah and his sons, and said unto them,
Be fruitful, and
multiply, and
replenish the earth.
How can one be fruitful and multiply and replenish the earth without doing so with the opposite sex?
Adam was legally married to Eve by God and it is recognized in this verse:
Genesis 4:1,25
1 And Adam knew Eve his
wife; and she conceived, and bare
Cain, and said, I have gotten a man from the Lord.
It is against God's law to have sexual relations outside of marriage and that marriage must be between those of the opposite sex:
Ephesians 5:3
3 But
fornication, and all uncleanness, or covetousness, let it not be once named among you, as becometh
saints;
Jude 1:7
7 Even as
Sodom and Gomorrha, and the cities about them in like manner, giving themselves over to
fornication, and going after
strange flesh, are set forth for an
example, suffering the
vengeance of eternal fire.
Leviticus 18:22
22
Thou shalt not lie with mankind, as with womankind: it is
abomination.
Romans 1:24-27
24 Wherefore God also gave them up to uncleanness through the lusts of their own hearts, to dishonour their own bodies between themselves:
25 Who changed the truth of God into a lie, and worshipped and served the creature more than the Creator, who is blessed for ever. Amen.
26 For this cause God gave them up unto vile affections: for even their women did change the natural use into that which is against nature:
27 And likewise also the men, leaving the natural use of the woman, burned in their lust one toward another; men with men working that which is unseemly, and receiving in themselves that recompence of their error which was meet.
It has been revealed in these latter-days that the covenant of marriage can be an eternal bond if done through the sealing power of the holy priesthood and according to will of God. Marriage is an eternal union for those who obtain the sealing.
Doctrine and Covenants 131:1-4
1 In the celestial glory there are three heavens or degrees;
2 And in order to obtain the highest, a man must enter into this order of the priesthood [meaning the new and everlasting covenant of marriage];
3 And if he does not, he cannot obtain it.
4 He may enter into the other, but that is the end of his kingdom; he cannot have an increase.
God created man and woman so that they could come together in an eternal union of happiness. Anything outside of this is against God's law of happiness that he ordained for mankind.
Alma 41:10
10 Do not suppose, because it has been spoken concerning restoration, that ye shall be restored from sin to happiness. Behold, I say unto you,
wickedness never was
happiness.