People with high security clearances who cheat on their spouses should immediately lose the clearance, be de-briefed and probably lose their jobs - depending on the position.
I had a Secret clearance in my service years, which is not super-hard to achieve. But even so, it was drilled into us that infidelity and bad habits like gambling and such are signs of someone easily blackmailed by the bad guys.
Strzok likely had/has a clearance two steps above that and he is a train wreck regarding personal discipline.
Don’t leave Page off the hook. Is she the honey pot that instigates? What are her Russian ties?