You can file for a divorce based on the fact of adultery if your spouse has cheated on you by having sexual relations with someone who is not you, and you find it intolerable to live with your spouse. Evidence of the act (or intention of) including videos, photographs, SMS/email exchanges, reports from a private investigator can be produced to prove adultery. Ultimately, each case depends on its own facts, and it would be best to seek independent legal advice if you require advice on the best course of action in your circumstances.