There's nothing wrong with "self-serving" if it's to fulfill some specific purpose: help you plan a legal defense, help you protect your finances, help you determine INITIALLY if there is an affair going on, help you confirm "no contact" once that's been promised by the cheating spouse.
If it's just to vent, to befriend, or to titillate or -- conversely -- somehow punish yourself to hear the details, I wouldn't recommend it.
