peek over (someone's) shoulder

Translations
подглядывать через (чьё-то) плечо
I felt like my boss was constantly trying to peek over my shoulder, checking my every move.
Мне казалось, что мой начальник постоянно пытается подглядывать через моё плечо, проверяя каждое моё движение.
Definitions
To watch or observe what someone is doing, often secretly or without their knowledge, typically by looking over their shoulder. This can refer to physically standing behind someone to see what they are doing, or metaphorically to monitoring someone's actions closely.