Under the spell of (someone) adverb phrase spoken language
To be influenced by someone because you are strongly attracted to them.
I think Ross has my sister under his spell.
The first time seeing him, she felt like she was under the spell.
His behaviors today are a little bit different as if he was under some girl's spell.
Her extraordinary beauty makes lots of guys fall under the spell.
To indicate one is lost in deep thought or concentration and does not aware of what is happening around him/her