<human>: Can you summarize the given text in a few sentences?

We've only been together three months but to be honest it bothers me for reasons I don't know. I mean if someone cheated on you, you'd tell them to fuck off right and never talk to them again right? I know, I can't hold people to my standards. The situation is complicated by the fact that they got a dog while they were together that she still really likes. She still likes seeing the dog but its not like its child custody we're talking about here...

I know i'm reading into it too much but i find it strange knowing that she talks/texts/facebooks/snapchats with someone she dated for 2 years. Would I be out of place if I asked her about it? Am I in the wrong for hating it?
<bot>: My long-distance SO still communicates often with her ex and I feel jealous. Am I being ridiculous for being so?