I think most people (in certain age brackets or demographics, anyway) started out in mono relationships and discovered poly afterward, so I see nothiing wrong in letting your interest in a momogamous person be known.
The world opens up... when you do.
Oh, oh, can't you see? Love is the drug for me. ~Bryan Ferry
"Love is that condition in which another person's happiness is essential to your own." ~Robert Heinlein