Article snapshot taken from Wikipedia with creative commons attribution-sharealike license.
Give it a read and then ask your questions in the chat.
We can research this topic together.
Obsessional jealousy is jealousy that is characterized by intrusive and excessive thoughts, and may be accompanied by compulsive checking of the partner. It is not classified as a mental disorder in the psychiatric manuals DSM or ICD, but it is mentioned as an example of how obsessive compulsive disorder can present itself.
Presentation
Its characteristics are:
Little resistance and distress associated with obsessional thoughts