Like Kogjin said, she may suspect already. If you've taken the leap to cuckolding, and it worked, think of this as the next leap.
As long as my wife and I have been in this lifestyle, she still feels a little threatened by the young, female flight attendants I fly with. Do I fuck the young, female flight attendants? Yes. It doesn't happen often, maybe two or three times a year.
Nevertheless, she has told me, given the choice, she would rather me have sex with a gay, male flight attendant than a female flight attendant. I prefer the females, but I do both. Either way, my wife, truly, has nothing to worry about. These young guys and girls are just looking for some physical attention. Much like I was when I was their age.