시부모가 · 시부모를
parents-in-law (husband's parents)
Example
주말마다 시부모님을 뵈러 가요.
I go to see my parents-in-law every weekend.
Word parts
시 husband's family+부 father+모 mother
시- marks the husband's side: 시아버지, 시어머니, 시댁.
Good to know
In polite speech, almost always add 님: 시부모님.