This one isn't too deep but I keep thinking about whether or not I was in the wrong here. 

For some background, I'm a 23 year old male. I was riding the train back from work when a middle aged woman and her teenaged son sat next to me. 

I noticed that the woman had a family pass, which is good for up to 4 people (2 adults and 2 children). 

I asked her in a somewhat joking manner (kind of with a cheeky smile as I spoke) if I could say I was with them so I could ride the train without having to use one of my tickets. 

She said "absolutely not" with a bit of aggression and gave me a nasty look. I was a bit surprised by her reaction so I kinda laughed and said "oh well, it was worth a shot" and just listened to music for the rest of the train ride. We did not interact for the rest of the ride. 

So I've been wondering, AITA? If the situation was reversed I would have let someone hop onto my family ticket without question; the conductors just go by quickly and check so it's not like anyone would have got in trouble. 