You fucking luck out usually.
Girls with tits that big are usually chased after a lot in high school, and then there’s the game of should you be the first and be able to keep her for the long haul? Or do you bide your time and wait till 2nd-3rd year of college to get on that with the better chance of keeping her?
Either way more often than not, the big totty short girls are all snagged up in their school settings. So you could just kill the current bf I guess? The bf keeling over is actually your best shot.
OR the alternative. Find a cute enough girl who’s single, and maybe front some implants one day. I’d strongly consider the implant option depending on how far the technologies come.