At the time of the applicant's application for a financial variation order (cessation) my partner and I had been cohabiting fo 13 weeks. We are now about to hit the final hearing some nearly 2 years down the line - due to his constant delaying tactics and sadly the planned final hearing in March being postponed for COVID reasons. It is clearly easier to prove an established relationship now for him, but what impact will the judge make of the date of application rather than now. Has his case got stronger through his constant delays? On all the other aspects of the case, his affordability and her lack of it, we are confident. Nor is there any financial mingling between us.
Much depends on the wording of the existing order - especially if it makes a specific reference to cohabitation as a trigger clause for ending maintenance.
The decisions in financial hearings do take account of history - but they tend to place more importance on the up to date situation (i.e. things as they stand as at the date of the hearing).
So I suspect that if cohabitation is a major criteria in the decision - they will base it on the length of cohabitation as at the hearing date and the stability/permanence and financial impact of that relationship.