Walk in on someone – to go into a room and see what someone is | Английский каждый день @by_english

Walk in on someone – to go into a room and see what someone is doing, when they did not want to be seen.

Застукать, наткнуться.

Например:

She walked in on me when I was getting undressed.

Она застукала меня, когда я раздевался / раздевалась.