Oral Sex
It is a very sensitive topic, there is no specific text (nass) to deem it haram, however it is disliked due to multiple factors. Many of the jurists deemed it permissible. I would advise you to go through this article and apply which suits you best. This also has a section on the aforementioned topic. Reminder: This article is written from the perspective of Traditional scholars. https://systemoflife.com/etiquette-of-intimate-relations/