<human>: So me and my girlfriend dated for almost 3 years. She broke up with me about 8 months ago and I went through the whole process of little to no contact, started exercising 6 days a week and got into the best shape of my life. Needless to say I and was doing ok. 

About 2 months ago I found out my ex was secretly screwing around with a good friend of mine. After I found out she had me meet with her, where she what seemed like sincerely apologized and asked me to "keep the door open" to our possible future, so I forgave her but we remained separated. 

About a week ago I encountered her once again and she asked me about getting back together with her and things really seemed optimistic as we decided to slowly start our relationship over. 

One week later she basically tells me she loves someone else. Now I feel worthless, one week into our rekindled relationship I am once again cast aside. I no longer want to be with her again, but the feeling of sorrow is stuck with me. Any advice on how to bounce back from/understand this would be appreciated. Thanks reddit.

Summarize the given text in a few sentences.
<bot>: Why would she ask me to get back together with her only to tell me she loved someone else a week later and be dumped again?