He must be cheating... That's the only explanation!

The mysterious calls...

The clandestine meetings...

The way he sneaks off at odd hours...

It's just that you need to catch him red-handed...

'Little did you know that was not the case on the contrary he's very loyal. He just wants to protect you from his other life...`

'The one where he kills people for money...`

Which leads you to the present where you looked through his phone and followed him in your 'breaking up with him outfit' just to find the woman he snuck off to the bathroom with laying on the floor with a bullet in her head...

"What are you doing here, dear?" He answers calm as ever. Like he isn't standing over a now dead body?