Did I get stabbed in the back?

Okay so when me and my ex were together we had our issues but what didn't help was her best guy friend hearing her rant after a fight, and instead of taking this as a rant he took it as fact, suddenly hated me, and basically convinced her that i was evil.

Then in August we broke up. She lived with me so while she looked for a house, she stayed with him, for what ended up being about 4 months.

She later told me that they started seeing each other in October, while she was still there. And then started dating in January.

I feel like to move on to him she may as well have cheated on me.
And I've always suspected that he was always in love with her. And that he took full advantage of her in a low point.

What are your thoughts?
Did I get stabbed in the back?
Add Opinion