I have an open relationship so no issues covering what I do.
I use a dual SIM phone with parallel apps. I have a cheap PAYG SIM in slot 2 and a separate folder with 2nd versions of communication apps like SMS, WhatsApp and a phone dialler that keeps all messages and phone records from the 2nd SIM self-contained from my main number.
I can also just enable/disable the 2nd SIM whenever I want.
It's a neat solution and very discreet, but it would require a bit of technical fiddling around to set it up.
