to please someone in order to obtain a favor or benefit
who exaggeratedly praises someone for the sole purpose of obtaining a favor or a benefit
a person with wrong motives, is with someone just for interest, hypocrite, flatterer. Some synonyms, words or similar expressions can be hypocrite, flatterer, interested
Used in US as well
"Amber Heard is being sobona to Johnny Depp as she owes him 13 million $$."