The above answers are right on the money. However, also bear in mind that a divorce petition is a public record and that everyone and anyone can have access to your court file- meaning if you do not wish to air out your dirty laundry in front of everyone, I would suggest not adding adultery as a ground for divorce. As mentioned above, you gain nothing by adding adultery to the petition.

Grounds for divorce in Illinois are by statute irrelevant as to issues relating to a possible award of maintenance (alimony) or the division of marital assests. However, although the fact that a spouse committed adultry my not have a direct bearing on your case, it may have an indirect one if child custody or visitation is at issue or there is a claim of dissipation of marital assests.

I agree with Gary. You can use adultery but it is very difficult to prove.

If you are trying to make a point with the adultery, you will need to prove it. To prove it, you don't need to be in the motel room but if you show them going in and coming out in the morning, that should do it.

Illinois is a no-fault state, so you don't have to prove it. Read the statute, 750 ILCS 5/401. You should state irreconcilable differences as one ground, then state adultery as an alternative ground. As the other answers stated, it will be hard to prove adultery, so if you can proceed on the irreconcilable differences ground it will be easier.

If you really want to divorce her, include a ground that "irreconcilable differences have caused the irretrievable breakdown of the marriage, and that efforts at reconciliation have failed." This basis is only available if you have lived separately for 2 years at the time the judgment of dissolution is entered, or you have lived separately for 6 months and both spouses waive the 2-year separation requirement.

She does not have to be pregnant to prove that she committed adultery. If she is not willing to admit it, then you will have to use circumstantial evidence such as testimony from witnesses to whom she admitted the affair, phone bills, credit card charges, photographs of her with the other person, etc. You may need to engage the services of a private investigator in order to garner sufficient proof.

If she is not admitting the affair and she is not pregnant, is there any hope of reconciliation? I would strongly recommend that before you take such a decisive step as filing for divorce, at least see a marriage counsel by yourself and explore whether reconciliation is a possibility. I'm sure you are hurt and reconciliation does not feel possible at this moment, but you will never know unless you explore it.

use mental cruelty. illinois is not a no fault state. there must be a legal reason, grounds, proven to end a marriage. one such ground is irreconcilable differences. there area about 14 others. adultery is hard to prove. it cannot be her admission. she needs to be caught in the act, almost.

read 750 ilcs 5/401 to see all the grounds.

in setting support and dividing property, fault is not one of the factors. it is in some states. not here.,

If you are trying to handle your own case and use adultery then it is not going to be easy for you to prove. Then again, in Illinois, there is absolutely no good reason to use adultery as your grounds because this is a no-fault state meaning you do not need to prove fault to get divorced. You will not get any more of the marital estate if you prove adultery because grounds have nothing to do with the disposition of the marital estate or property. You are already over your head here so do yourself a favor and hire counsel with divorce expertise.