Flower, yes she or he can spend hours on line on the computer, OR they can spend hours on the phone. OR they can do what they used to and meet at a hotel, in the city, go to an x-rated movie theater, go to a red light district, etc.
Way before your time there was an x rated movie theater around the corner from Mirrer Yeshiva. Many moons ago there was a sheitel macher in Brooklyn who set unhappy married women up with all too willing men. I know, I once sold sheitlech and I got a phone call from a man asking me if I would set him up. I was so shocked and shaken up I hung up on him and called my husband. I was so disgusted. I hadn’t heard about this woman but he had heard the rumors. I wanted to close down my business but he said he needed the financial help and asked me to forget about it.
This all happened way before anyone even dreamed of a computer. So it will happen whether one has the internet of not. If someone is unhappy in their marriage and they want to find a way to get some happiness in their lives, they don’t need a computer to do it. Does the internet make it easier? Sure, it makes everything easier, but again even those who don’t have a computer will find their way to happiness if they want to.