Can a very handsome man truly love a plain woman?

For the past 6 months I have been dating a really great guy. I am 34 and while I don't think I am ugly I'm no beauty I'd say I was homely or average and not into make up or fashion! My boyfriend on the other hand is 35 and drop dead gorgeous, he was actually a model in his 20's but now has his own successful business organizing and taking people on adventure holidays which is where I met him. Things have been going great and recently he has spoken about marriage. He is wealthy and I'm a cellist and never have much money, I'm pretty shy too. When we are together I feel wonderful as being with him feels so right but sometimes people, especially other women look at us and I know what they are thinking that he could do so much better than me. Sometimes I wonder when he will finally wake up and see that he is punching well below his weight with me! Is it possible for a beautiful man to truly love a plain woman?