Ok a little background. My girlfriend and I have been going out for 5 years and live together , she's cool, good looking, and ambitious so I have no complaints on that front. One of our friends from high school, let's call her Ashley , used to like me -would always flirt with me, show skin etc, and I almost started dating her right before I started dating my current gf. Im 24 now (well out of high school), and about a year ago me and my girl noticed that whenever Ashley came over , articles of clothing would end up appearing in our apartment in random places. Ashley would also make comments that basically insinuated that I was a bad boyfriend , although they would appear to be jokes so I couldn't bite back too hard. After we found the third article of clothing in our apartment , my girlfriend and I decided to stop hanging out with her. This solved the problem- the clothes stopped appearing . Fast forward six months later , my girlfriend saw Ashley at a party, reconnected and they are hanging out again now . My question is why would she willingly hang out with a girl who seemed to be trying to sabotage our relationship , and use to like me ? Sorry for the formatting , I wrote this on my phone .