<human>: Can you succinctly summarize the text in 1-3 sentences?

I've always felt secure in my relationship. Until I found that he reached out to a girl he once had a thing for. It was innocent, he would be speaking at a day event she would be at. He swore she was just a friend. And said he only saw her afterwards for a brief moment to say hello while everyone else had drinks. It shattered my confidence in him. I feel guilty for even questioning him because he's never done anything to make me question his honesty. We are engaged. I just don't know how to get rid of this tarnished idea of trust. My logic tells me I can't be this paranoid for absolutely nothing. But at the same time I know I'm not the most secure woman on earth. So maybe it is just me. 

Please go easy on the berating!
<bot>: Fiancé reached out to old crush. Made me question my trust for the first time ever with him. Is it just my immature insecurities?