Use the time machine from the previous reply, then make everyone from like around WW1 to present keep voting for staunch social conservatives in politics and in school districts. You boyfriend will then grow up in a wonderful, Mayberry RFD-like society almost unimaginable today: with plenty of strong institutions like his extended family, schools, churches, and probably most important - entertainers - all supporting and expecting him to save himself and keep himself clean and unsullied (doctors would only prescribe birth control to married couples who had already had children) all until he meets the one "right girl" - YOU. That way, there won't be any ex-s to worry about at all, and in that world they'd all be nice girls if you met them, not evil. They'd probably only have gotten as far as playing cards, under the watchful eye of a chaperone...
But of course, you will have to be just as chaste as this gentleman - remember, he WILL be a dashing and romantic gentleman, and he will court you with grace and panache!
Best (or in this thread: WORST) anime-related place to retire?