<human>: We have been together for almost a year and a half and last night she told me that she feels like she has an emotional connection with her friend as well (I don't know who this person is). She said it just sits there and she doesn't do anything about it and it hasn't bothered her so far, but felt kind of overwhelmed by it last night. Apparently thoughts pass through her maybe as often as once a day, which she described mostly as what-ifs such as what if I had never come around, etc.

I'm her first long term relationship, everything else has only been hookups for for a couple of months. She thinks that she may be having these thoughts because she found shorter term relationships fun before she started looking for getting serious with someone.

She told me that she doesn't see him as someone she could be with for a long term relationship, maybe only a few months, but is confused as to what we should do and so am I.

If the thoughts continue to overwhelm her, I think she would eventually have to choose between severing their friendship and severing our relationship. Even if they don't overwhelm her again, I'd be concerned that it may become a problem again, though I can't say for sure.

Has this happened to anyone before? Am I missing something in my thoughts about this? What are your thoughts? Thank you in advance.

Summarize the given text in a few sentences.
<bot>: SO told me she has "what-if" thoughts about her friend and we're both confused as to how to proceed