A state of emotional connectedness between two people, where one or both of the individuals are overwhelmingly possessive.
You know your in a strangulationship when your girlfriend is overbearing. My girlfriend never allowed me to be alone with her sister, initially having no attraction to her sibling I naturally thought this behavior was ridiculous. However, after years of overwhelming mistrust her sister and I would occasionally flirt to poke fun at her ridiculousness. This ultimately resulted in wild unadulterated sex, with her sister, in the upstairs restroom at a family gathering.