Name changed for this.
No children and assets (our home) were split 50/50 as were pensions (his was much larger as Id had career gaps so I've benefitted here) to be fair my share did allow me to purchase a suitable house for myself mortgage-free. My income was much higher than his at the time of the divorce.
However, he indicated on form e that he was not planning on cohabitating with anyone within 6 months of divorce and he has moved in with a new partner in her rented property.
Have a realistically anything to gain by taking any action on this?