SUBREDDIT: r/relationships
TITLE: Me [19 M]: my 3 year [19 F] LDR girlfriend, cheated on me and left me for [37 M] in an open marriage.
POST: I posted about this earlier, but it was way too long for anyone to actually want to read.

Basically, my high school sweetheart and I decided to have a long distance relationship when we left for college. The first year was great, came back for the summer and everything was wonderful. The next year she met this married man (in an open marriage) who she fell in love with and cheated on me with for two months. She came clean over winter break and said she wanted to be with me, only to leave me for him a few weeks later.
TL;DR: 
The love of my life left me for a (open) married man, and she could never tell people about the nature of their relationship. Not sure how I should feel. I still want her to be happy.