You better act like you know
That I've been through worse than you
She tells him to check himself when she says “you better act like you know”, and she is also telling him that she’s been through way worse than this guy when she says “I’ve been though worse than you”.
She may just be trying to boost her confidence and pretend she’s not the one ‘facedown’ due to the fact she know’s she can get through this. Since she’s dealt with worse, this will not beat her down.
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