Could women want a relationship with a man who looks extremely young?

That depends on the type of woman you are interested in. If you really do look like a 16 year old, there could be some ways to make you look a little older. Change your image a little bit to make you look more like your in your twenties. But if the girl really does like you, she'll accept you for who you are. So, I'm going to say that yes, a woman in her twenties could love a man who looks like he's 16. Hope this helps. :)