Paul urges us to flee from sexual immorality (1 Cor 6:18), reminding us that whoever sins sexually sins against their own body, which is a temple of the Holy Spirit. (1 Cor 6:18-19). We live in a society which does not really recognise sexual immorality anymore. Everyone is free to do as they please sexually and if you say otherwise, you are likely to be criticised and condemned.
Nonetheless, the Bible urges us to avoid sexual immorality (1 Thess 4:3) and gives us a clear picture of marriage between a man and a woman as the only sanctified context for sexual activity. Jesus reminded us that sexual immorality starts with our thoughts and attitudes and we must therefore do all we can to maintain purity and holiness in every area of our lives, including this one. Far from giving us prohibitions to spoil life, God gives us commandments to protect us and others and to mirror His undying love for us. Embracing His restrictions sets us on the path of life and actually leads to freedom.