In the past I've been waaay too soft with setting boundaries in relationships (FWB or LTRs), so I figured I would post here to get your input. I've been hooking up with this new girl for a week now. We'd meet at her place for a bottle of wine and end up having sex. In the morning she'd make us breakfast and I'd be on my way. Even though its been a short while, I can tell she's getting super attached, buying me Xmas gifts, inviting me out to parties etc. All around a good girl. However...

Tonight we agreed to meet up in the evening at 930. At 730 she messages: hey i actually decided to go out drinking haha. You want to reschedule? Maybe lunch tomorrow? We text in a foreign language so its difficult to translate the tone of it, but the essence is-- hey something better came up, so I'll do that instead. I give women the benefit of the doubt the first time they flake if they offer to reschedule, but the tone and excuse was disrespectful so I decided not to respond tonight and go for the soft next. I know some guys reserve this for more severe behavior (drama etc), but personally flakiness of this sort is something that really bothers me.

I'd want your guys input on this situation and how you would do to handle it?