Wife doesnt want me to go abroad for uncles wedding?

No you're not being unreasonable. I think your wife is probably just pissed off that she can't go and wants to make it clear that she's unhappy with your intention to go without her. It's a woman thing. She will make sure you understand that your decision and the circumstances are not pleasing to her, and that you can fully expect to be nagged, annoyed, and bitched at for the week before and after your trip. So enjoy your week away and have fun at the wedding.