be out of (one's) league

To be a poor match for someone, often because someone or something is considered superior. Although it can be used in other situations, this phrase is very often applied to romantic partners that are not similarly attractive or wealthy. I can't believe that average-looking guy is dating a supermodel—she is totally out of his league! I've only been working in IT for a few months, so that advanced position is really out of my league. I know that people think my wife is out of my league, but I really don't care—we love each other and that's all that matters.