Is he allowed to look up your file? That doesn't seem right to me...
I was once hated by my bfs parents --because after only dating a lil while, we came home drunk and ended up doing it in there lawn...And then when they made us come inside his mom tried to help me get pjs on....And I had to explain to her that I never wear underwear....And just a bunch of other stuff that a parent doesn't want to hear from there 23 year old sons 16 year old girlfriend...---oooooops!
But now they just can't get enough of me =) I gained there respect over time and made my way into the good books..
Seeing as they've never even met you, I wouldn't take it too personally. They don't really know what you are like, so just wait it out...And in the end, what reallly matters is b/w u and ur fiancee.