I thought this was a milkweed going by the flowers and the scent but I can't find it listed in any of my Ontario Milkweed sources...quite vine-like...any ideas?

I would say it is Matelea genus but not sure which and I don't see one that is listed for Canada.

Cynanchum nigrum (Black Swallowwort) or Cynanchum rossicum (Pale Swallowwort). Only difference is C. nigrum has "fuzzy petals" and C. rossicum has "smooth petals".

Either way, you'll want to get rid of it: http://ontariowildflowers.com/... lists them as "highly invasive".

Pale Swallowwort...thank you!! Good thing I didn't dig one up and bring it home

Another nasty plant from across the pond, and appears to be heading south according to range maps.