meeting the dad

Hi everyone my bf dad lives in thailand, he wants us to go out there in december for a three week holiday but all he has told me about him is bad, and the same with his sister how am i meant to go out there and forget everything my bf has told me?
what about if he dont like me?
omg im so nervous thinking about it. i really want to go to thailand but feel that my bf will see his ex fiancee too an fall back in love with her, my bf prewarned me she might come to see him. what would i do?