Wa alaikum salam,
That is a lie which some people who are not willing to submit completely to Allah have invented and some of the people who ignorant about the Qur’an have followed them in this belief. Homosexual marriage is not allowed in Islam in anyway and its impossible to try and justify in any way. Once I read something about someone using the linguistics in surah Al-Ankaboot to say that their sin was rape and not sodomy (and maybe they were raping people too, idk) but this opens up doors to say that Islam is an evil and barbaric religion (I’ll explain why soon)
The Qur’an is an amazing book, Allah says
"And We did not send before you any messenger or prophet except that when he spoke [or recited], Satan threw into it [some misunderstanding]. But Allah abolishes that which Satan throws in; then Allah makes precise His verses. And Allah is Knowing and Wise.
[That is] so He may make what Satan throws in a trial for those within whose hearts is disease and those hard of heart. And indeed, the wrongdoers are in extreme dissension.
And so those who were given knowledge may know that it is the truth from your Lord and [therefore] believe in it, and their hearts humbly submit to it. And indeed is Allah the Guide of those who have believed to a straight path.” (22:52-54)
The Qur’an must be completely coherent, so what you will always find with any deviant belief which is derived from the Qur’an is that it does not fit in with the coherency of Islam and the Qur’an because Allah has made his verses precise. So if we were to now take the assumption that rape was the sin of this nation and look else where in the Qur’an we find that Allah says
“Indeed, you approach men with desire, instead of women. Rather, you are a transgressing people.” (7:81)
And this ayah would then imply that Allah is saying “why rape men when ive allowed you to rape women?” and this goes against even the most ignorant muslims understanding of the deen because we all recognise rape to be an evil thing.
Muslims who say things like this need to stop making islam suit their desires and seem more appealing to the west tbh
"O you who have believed, enter into Islam completely [and perfectly] and do not follow the footsteps of Satan. Indeed, he is to you a clear enemy." (2:208)
hope that answers your question :)