There are stages to imprinting, especially if the shape-shifter imprints on a child, or otherwise someone very young. It starts with direct eye contact with his imprintee:
1st stage—If the imprintee is young, the shape-shifter will act as an older sibling.
2nd stage—As the imprintee grows older, the shape-shifter will also come to be their best friend.
3rd stage—They become intimate friends, meaning, their feelings for each other are changing into romantic feelings. This stage may or may not happen to the imprintee, but the imprinter will fall in love with his imprintee. They will not "see" any other woman at all. Their imprintee is all he cares about and he will love her even if she rejects him.
4th stage—When the imprintee is old enough, the shape-shifter's feelings grow into romantic love.
-from the page Imprinting