Are you sure you want to use adultery as the reason? I only ask because that is what I was going to do, I was adamant. Stbx had admitted it both verbally and in an email. I was then convinced by a solicitor that it was better to go for inappropriate relationship as 'unreasonable behaviour' instead.
I understand that with adultery, the respondent has to admit the allegation on the answer to your petition. So if that person suddenly gets the 'hump' they could turn around and deny it and you get embroiled in either a defended action (hard to prove)or have to start all over.
People (courts etc) know exactly what is meant by 'inappropriate relationship' these days but you will be seen to be holding the moral highground which can pay dividends later on.
The moral highground is a nice place to be.
If you really need a bit of revenge, you can always toss in another issue (as long as it is truthful) on the same petition. In my case stbx actually came back at one point and asked that I change it to adultery, because that bit did not bother her or her new bf. It was the other thing that she would have rather not faced or have bf know about.
Well, as many people will tell you revenge on a piece of paper that few people will see, is ultimately unsatisfying.
If I were to contemplate revenge it would be rather more spectacular...
The moral high ground is mine by definition (I won't go into gory detail).
I am interested to know what 'dividends' it would pay though, as I have not seen any evidence to support this.
I am also sure that she will not defend the petition as she is keen to proceed as quickly as possible and I have explained the cost and time implications of defending, also that the actual reason for petition is of almost 'no consequence' to any other part of the proceedings.
Strange though, the solicitor I had an initial meeting with was definately guiding me in the direction of adultery because unreasonable behaviour is a matter for the judge to agree (to a point) and can also be defended.