But the man's enjoyable evening out Saturday quickly took a violent turn.
"This was right next to my friend, so I put my arm over her to make sure she wouldn't get hit," said the man, who asked not to be identified out of concern for his safety.
The man's wife stood up to get away from the group but left her iPhone on the seat. One of the teens snatched it and said, "I'll take this." The man said he told the teen to give the phone back, but the teen ran for the door.
"Then I got swarmed by the whole group," the man said. "They were just pounding me. I was just trying to protect my head as much as I could, I knew there was nothing I could do about it. I was stuck. They did a number on me."
The attack lasted just seconds. The group jumped out as the train pulled into the Lake Street stop.
The man said he, his wife and their friend followed the teens onto the platform, where other riders were waiting. "They saw me fall out of the train, covered with blood, and they saw the group of kids run," he said.
Several people called 911, but the man's group went up to the street before any help arrived and after several minutes found police officers who called for an ambulance, he said.
The victim was taken to Northwestern Memorial Hospital and treated for a concussion, a fractured orbital bone under his left eye, two cracked teeth and a cut over his left eye that required six stitches, he said.
The man, a computer engineer, said his doctor has advised him not to go to work for two weeks. He said he has seen three doctors so far and may have to undergo eye surgery when the swelling goes down.
"It's going to be a lot of money," he said.
The man said he is convinced the group set up a ruse to rob them or simply to attack them.
"It was so incredibly, perfectly timed," he said. "We saw the other kid get up, the one who was being beat, and he got up and looked unscathed and just got up and left. There's nothing that leads me to believe that this was an accident."
The man said the CTA should have better security. CTA spokeswoman Catherine Hosinski said the agency provided police with surveillance video taken from the platform that evening.
Over the year, officials have added an additional 1,800 surveillance cameras to the system, and police have beefed up their presence on CTA lines, Hosinski said.
Police have released surveillance photos of the suspects, who remain at large. The photos show the attackers at both the platform and turnstile levels of the subway station.
The man said he wants police and the judicial system to hold the attackers accountable.
"They need to get the word out and they have to start convicting these people instead of just taking them in and letting their parents pick them up," he said.