Sounds to me like your wife is already interested in the hot-wife-cuck fetish.
Possibly terrible advice but I'll give to anyway:
Secretly do some homework on hotwife/cuck fetish, you can tell her later if it was a surprise success or totally !not!
The best way to be introduced to a new fetish is as masterbating material (you have full control in stopping it, with no power dynamics or future repercussions)
Yes mommy ๐ฅต