Right now I'm dealing with a girl who's super flaky. We met back in March and talked for a while, then sexted a bunch. Two times in a row I invited her over to my place and she accepted, only to back out at the last minute (like an hour before she was supposed to show up). The third time we actually met and hooked up. I invited her over again a few days later and again she flaked, so I wrote her off.

Then she messaged me again at the end of August wanted to meet up so we did. We met at a bar then went back to my place and the sex was great. So good in fact that she spent the night and we ended up fucking throughout the entire next day.

Since it went well I invited her over last Saturday and she agreed, only to message me at 4 pm on Friday saying, "Can we meet tonight? I'm busy tomorrow". I was pretty annoyed and told her so but I also wanted to get laid so I said that was fine. We again went to my place and fucked, this time she took off right after we were done saying she needed a good nights sleep.

On Sunday she messaged me saying that she wanted me to come over to her place for once, offering to cook me a nice meal. We made plans for 7pm on Wednesday (today). She just messaged me (at 3 pm) asking if we could push it back until tomorrow or Friday because she has to work late.

The sex we have is amazing and I'd like it to continue but her flaking is really pissing me off and I'm worried that by allowing her to do it I'm just reinforcing the behavior.

Anyone have thoughts on how to deal with this other than writing her off completely?

Edit: After sleeping on it for a few days I decided to hard next her. I just don't have the tolerance for someone wasting my time.