Oh, yeah, I know...I should have just said "poorly worded" instead of inappropriate. I suppose "inappropriate" implies ill will. I think he's a good guy, and I'm sure his intentions were good. The thing is...the twins' personalities are very dissimilar. If you remove the identical twin aspect all together, it seems an even stranger thing to say.
"You are very beautiful inside and out, that is why I married your sister."
It almost seems like he's saying that since he couldn't have her, he married her twin sister. I'm actually more amused by it than anything, really. The fact that they are identical twins really doesn't reduce the weirdness of it for me. And, he's someone whom I would expect to be better at expressing himself, but that doesn't mean that he is...clearly.