imo it doesn't even matter if she has banged a thousand guys as long as she makes her experience worthwhile to you in some way(like say, an ass than can take even the biggest of d!cks or by ****ing you on the first date even though it was just a walk in the park or giving you the best bj ever, etc.).



too much mileage is just a function of her behavior after a million lays, for example:



-if she treats all guys like sh!t by default because she's bitter about dozens of pump and dumps



-if she artificially makes you wait longer for sex as an over correction or because she's afraid you'll find out she's a slut



-if she intentionally holds out on you so that you don't suspect she's a slut (this could be anything from acting like she has a low sex drive to not wanting to do anything kinky so she doesn't come off as experienced)



- the obvious stuff like having a bunch of kids, having any diseases, being an active porn star or hooker or something, etc.



- this is an important one: any key behavioral or personality problems (BPD, daddy issues, sex addiction, drug addiction that leads to crackwhoring, etc.) but technically speaking, since she probably had those problems since before she fvcked half the town, it's not technically an issue of milleage but rather the cause of milleage



-or the worst one of all, if she turns over a new leaf and "doesn't do that kind of stuff anymore" meaning everyone else got the drunken party slut and you got to date the nun, who has the same amount of milleage but none of the fun