I was reading it as, “now this dress has the capacity to have had boy cooties on it” which I would have thought, in my limited frame of reference, that would make the dress more gross and perhaps at the very least less desirable for those who are inquiring enough to care about “who has worn this before me”. but I guess if you think about it from the perspective of pulling it off, wearing it well and it fitting their personal taste well for the “first time for that dress”, for whatever that’s worth could be the other interpretation which could reasonably be something I could see someone being excited about