coming out as bi inside an existing ENM marriage, how did you do it

me and my wife have been ENM for about 4 years. weve done basically every configuration including her with other women several times. last month i finally admitted to myself ive wanted to be with another man for years and have been quietly editing it out of my own head. now i need to tell her and im completely twisted up about it. like... weve done so much together and ive been hiding this small thing the whole time. shes incredibly open generally so logically i know shell be fine but the part of me thats been hiding for 15 years doesnt believe logic. for the people whove come out to a long term partner inside ENM, how did you do it. did you wait for a moment, did you just blurt it, did you write it down. and did it change anything between you afterwards