Poppy,
It is very unusual - but not unheard of for this to happen.
There are typically two elements to the clean break:
- a clean break on captial (ie assets / debts have been split once and for all)
- a clean break on maintenance (ie. a lump sum has been paid in place of any ongoing maintenance)
What is quite common is for people who have a clean break on the capital - but who still have a maintenance agreement in place - to go back to court to vary or to stop the maintenace (due to change in circumstance) and at that point the court may sometimes order a new additional lump sum payment to set aside the future maintenance obligation.
To go back to court to get more capital after a capital clean break seems very unusual.
You may find this interesting.
http://www.wikivorce.com/divorce/Latest/Second-bite-of-the-cherry.htmlbut later this decision got appealled...
http://www.dailymail.co.uk/news/article-470774/Millionaire-wins-court-battle-unfaithful-wife-
claiming-fortune--30-years-divorce.htmland in any case the original "second bite at the cherry" award was only possible because the wife had a lifetime nominal spousal maintenance order in place.
So I really can see absolutely no basis for your ex coming back for more UNLESS you are currently paying him spousal maintenance.