<human>: Be sure to explain in detail with line breaks.
Hey guys,

4 years ago My ex left me for someone else, I was heartbroken; but ultimately moved on, but did not date either for the 4 years.  After 4 years she suddenly comes back saying she wants to start something up.  I have to admit I was naive and because she was my 1st and only even till this day I had a soft spot for her.  Things went well for a month and a half before she suddenly felt that we both changed too much and broke it off. The day after we broke it off she was already posting pics of her partying with another dude.  Not sure if there's any good advice here, just wanted to share.  Beware guys, exes have the ability to chew you up and spit you out without even blinking.  I'm glad I can now completely move on, but man is this a depressing feeling.

Can you give me a shortened version of the text?
<bot>: Ex who was my first and only came back years later, only to end it suddenly less than two months in.  Beware of the exes.