I understand your concern SumanJoshi89. I am a nepali girl and have been living in US for few years. It's good to think about your size before the wedding. But I don't think your future wife will be comfortable talking about that. You could try. IF she is open mind then you could talk with her. However, girls are more satisfied if you are passionate and romantic. Show her how much you love her. Express your feelings. Sex is both physical and psychological. So size should not be a problem. It's not a problem for me even I have been in US for a while. I perfer a guy who understands and loves me more than a guy who satisfies me in bed. So be confident and good luck. It will work out.