If she was in a relationship with you and now she isn’t, in her mind there’s a reason.
Let’s say she broke up with you because you cheated on her. In that case it’s probably a bad idea to try to get her interested by having other girls flirt with you.
If she broke up with you because you were a wuzzy, strong confident behavior and flirting with other girls might help you a lot.
It could also make her think that you are an even bigger asshole.
If you want her to be comfortable going to her place without invitation wouldn’t be very straightforward.