Theres a simple solution: dont use old routines, make "new" ones by varying the existing routines, or dont use other peoples material at all (goooo juggler!).
If you get the "oh ive heard this before" thing, i assume you can just go "oh yeah? i just learned it and wanted to test it out. what did you think of it?" and build the convo onwards, maybe reverting into a story of one time when two girls used the same line on you once, unless thats percieved as a DLV...
Not really sure. But at least thats an indicator of using some more personal stories and routines, instead of other peoples material from now on

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