Praise be to Allah.
The idea that “The Muslim is required to keep away from haraam things because he will find them in Paradise” is not correct if it is understood in a general sense, because not everything that Allah, may He be exalted, has forbidden to us in this world will be found in the hereafter. Rather that is mentioned with regard to a few things, such as the prohibition on wearing silk garments, the prohibition on drinking alcohol, and the prohibition on drinking from vessels of gold and silver. The Muslim will find these things in Paradise in a manner that is appropriate, by the grace of Allah, and they will exist in a form that is appropriate to that realm.
It was narrated from Abu Hurayrah (may Allah be pleased with him) that the Messenger of Allah (blessings and peace of Allah be upon him) said: “Whoever wears silk in this world will not wear it in the hereafter; whoever drinks alcohol in this world will not drink it in the hereafter; and whoever drinks from a vessel of silver or gold will not drink from such vessels in the hereafter.” Then he said: “[These will be] the garments of the people of Paradise, the drink of the people of Paradise, and the vessels of the people of Paradise.”
Narrated by an-Nasaa’i in as-Sunan al-Kubra (6869); classed as saheeh by al-Albaani in as-Silsilah as-Saheehah, no. 384.
If something that is prohibited has an equivalent in the hereafter, then some of the scholars are of the view that the one who does this prohibited action in this world will be punished by being deprived of it in the hereafter, such as music and intimacy with a woman who is not permissible for him.
Ibn Rajab al-Hanbali (may Allah have mercy on him) said:
Whoever fasts today and refrains from what he desires will break his fast with that after he dies, and whoever hastens to indulge in what has been forbidden to him before he dies will be punished by being deprived of it and missing out on it in the hereafter. The evidence for that is the verse in which Allah, may He be exalted, says (interpretation of the meaning): “And the Day those who disbelieved are exposed to the Fire [it will be said], ‘You exhausted your pleasures during your worldly life and enjoyed them…’” [al-Ahqaaf 46:20]. And the Prophet (blessings and peace of Allah be upon him) said: “Whoever drinks alcohol in this world will not drink it in the hereafter, and whoever wears silk in this world will not wear it in the hereafter.”
End quote from Lataa’if al-Ma‘aarif (p. 147).
Ibn al-Qayyim (may Allah have mercy on him) said, when listing the punishments that will befall the zaani (adulterer) if he does not repent:
He is exposing himself to missing out on intimacy with al-hoor al-‘iyn in the delightful dwellings of the gardens of eternity. By Allah, if the one who wears silk in this world will be punished by being deprived of wearing it on the Day of Resurrection, and the one who drinks alcohol in this world will be punished by being deprived of it on the Day of Resurrection, then by the same token the one who enjoys at haraam images in this world, and any pleasure that a person derives through haraam means in this world, he will be deprived of its likeness on the Day of Resurrection.
End quote from Rawdat al-Muhibbeen (365-368).
As for homosexuality and lesbianism, Allah, may He be exalted, has forbidden such things to His slaves in this world, and the people of Paradise are far above such immoral and obscene actions.
And Allah knows best.