get (one's) hooks in
To gain control or influence over someone or something, especially with an ulterior motive. Because of my family's fortune, my parents always worry that any girl I date is just trying to get her hooks in.
get one's hooks in(to) someone or something
and get one's hooks inFig. to obtain a strong and possessive hold on someone or something. She just can't wait to get her hooks into him. He finally got in his hooks and guarded her jealously.