If you wish to start Divorce Proceedings before you have been separated for two years and adultery does not apply then your only option is to use the fact of “unreasonable behaviour”.
Your Petition must demonstrate that the marriage has irretrievably broken down due to the other person's behaviour – you cannot cite your own behaviour!
This fact is frequently used as it is very often the case when a marriage breaks down that one or both parties can demonstrate that the other party has behaved unreasonably.
So what is unreasonable behaviour? It can cover more extreme behaviour such as domestic violence, mental and verbal abuse etc. but more commonly it is more mild behaviour such as rejection of a sexual relationship with the other party, lack of communication, lack of help around the home or with care of children, lack of emotional support, refusal to socialise with the other party or his or her friends or family...
It is important that the Judge is satisfied that this behaviour has caused the marriage to break down. This means that it is sensible to show how this behaviour has affected the other person and so it is usually sensible to include such wording as “this caused the Petitioner much distress”.
It is always sensible for the other party to see a draft of the Petition before it is filed so that if possible the particulars can be agreed and do not come as a great shock. This usually avoids delay and other problems within the Divorce.