In Jainism, sexual conduct is to be governed by non-violence (ahimsa) and self-control.

• For laypeople (householders): Sex is allowed only within a lawful marriage, with mutual consent and without causing harm or exploitation. It is ideally guided by restraint and responsibility, not by mere pleasure.
• For monks and nuns: Celibacy is a strict vow, so sexual activity is not permitted.

As for specific acts (like oral sex), there isn’t a separate canonical prohibition in the basic Jain teachings beyond the general guideline of sexual conduct within marriage and with ethical intent. The emphasis is on harmlessness, consent, fidelity, and self-control.

Note: There are no essential doctrinal differences between Digambar and Shwetambar on the basic principle that monks are celibate; both traditions stress restraint for laypeople and complete celibacy for renunciants.

If you’d like, I can share concise references from Jain scriptures on brahmacharya and lay conduct.