<human>: Can you give me the gist of the text in a nutshell?

We've been dating for over 18 months, and most of that has been long distance. 

I recently flew to see her and was staying at her house. I quickly learned that her father was unhappy that we were sleeping in the same bedroom and since then, she has pretended to be sleeping in the guest room. She acts weirdly around him when I'm there, and I thought I could understand - she's his youngest daughter, and it's a different culture. He doesn't want to talk about it with anybody, but still be upset about it, fine.

But recently when I suggested that we could buy some beers and snacks and watch a movie at home (instead of going to the cinema) she started acting weird again, and I finally questioned her about it. Apparently when I first met her father, I had 2 pints of beer, and he thought this was too much. I was upset at my gf for not telling me this sooner, and more upset that he thought that way - he's actively looking for reasons to dislike me. 

The toughest part is that I can't speak to him - we literally speak different languages. I still try to make the best impression I can, but I feel like it doesn't matter, and obviously my gf cares about her father's opinion, and I just want to make things work out. I'm trying to learn his language but it will take a lot of time!

I don't know what to do - waiting until I'm able to speak to him in his language isn't exactly an ideal solution. I feel like even if I do speak to him, he'll just critisize me behind my back for my poor language skills. I was told that it wasn't personal, and that he just wasn't comfortable with his youngest daughter (who is 25 now) dating somebody.
<bot>: GF's father is looking for reasons to dislike me, and I can't communicate with him. It's affecting our relationship since she cares so much about what he thinks.