I hang out with my ex and we had sex.
Is sex something you avoided with your ex before now?
She was so easy and sex felt boring wit her.
You could hang out with whomever you choose. Sex with an ex is always bad news, it never turns out well at the end of the day. You will regret it and hate yourself in the morning, so avoid her like the plaque unless you want to be bored the whole time.
I am bored of easy girls.
Then find someone that plays hard to get if you find easy girls boring.