ごまをする
胡麻を擂る
gomao suru

Godan Verb (ru)
Idiomatic Expression

1. to flatter; to toady (to); to curry favor (with); to butter up; to grind sesame seeds — literal

Usually Written in Kana
あいつ、上司じょうし胡麻ごまってやがる。
aitsu jōshini gomao sutteyagaru.
He is buttering up to his boss.
Other forms: