I definitely think it would help force people to actually COMMUNICATE with their spouse and work on things (or file for divorce) rather than just cheat. I wouldn't be opposed to punishing the person they're fucking either. Is it sad and just plain fucked up that a lot of people would really need this to get them to treat their spouse better? Shyeah.
No. Why the fuck should someone get arrested? I was legally married when I met my dh. My first marriage was over except the legality. What exactly would jail time do anyway except put a further burden On the taxpayers? Stupid idea.