I have always seen these myths as linked to the practice of bride stealing that seems to have been common (or, at least, not uncommon) during the archaic period in ancient Greece. This involved actual, or symbolic, kidnapping of a girl (or boy) from their father's house as a prelude to marriage or a recognised/formal homosexual relationship. Obviously, when actual the kidnapping was essentially just that. Apparently the symbolic version established the worthiness of the husband/lover as a partner for the prospective girl/boy.
I haven't found a good reference for this online in the brief hunt I just did, but I have read it in a number of texts focused on either Greek or 'homosexual' history.