In Jainism, every action and every intention creates karma, which binds the soul to samsara (the cycle of birth and death). Sexual conduct is included in this framework.

Why casual sex leads to karma:

• Karma is not just physical acts; it is the intention and the mental state behind those acts. Sexual activity driven by strong passion (kama), attachment (moha), or deceit creates negative karmic particles that bind the soul.
• The Jain path emphasizes restraint and self-control. Sexual activity outside appropriate ethical norms (for laypeople: within a loving, consensual marriage; for ascetics: celibacy) is seen as a violation of ahimsa (non-harm) to oneself and to others, and it fuels passions that generate binding karma.
• This binding karma manifests as future suffering or obstacles on the spiritual journey, and it increases the difficulty of achieving kevalajna (omniscience) and liberation (moksha).

Key ideas in simple terms:

• Karma attaches to the soul when actions are accompanied by passionate desire or deception.
• Casual sex, when it violates ethical norms or is pursued for mere sensual pleasure, tends to increase raga (attachment) and dvesh (aversion), both of which generate karmic bonds.
• The path to liberation is through control of senses, truthfulness, non-harm, and, for those who can, celibacy or faithful, ethical conduct as per one’s stage of life.

About differences between Digambar and Shvetambar:

• Both traditions teach that sexual misconduct binds karma. The exact texts and emphasis may vary, but the core principle—that uncontrolled sexual desire creates karmic bondage—is shared.

If you’d like, I can share specific Jain sutras or sutra-stotra references that discuss karma, sensuality, and conduct, and explain their meanings in a simple, traditional way.