My FIL is a racist. He would say he isn't but he is. To give background, I'm Irish, PILs (and DH of course) are English but they lived in Ireland for over 10 years when DH was little. We had the PILs to stay at the weekend while we did up the kitchen and FIL commented that I should say to my parents that I did the work myself and that I "didn't need to get a Paddy or a Pole in to do it for me." My response was (lightheartedly) "Well I did have to get a Paddy in, but the Paddy was me." He had no response for that. Thinking back on it I'm really annoyed that he basically used a racist term for Irish people in front of me. My main concern is that if he keeps making these sort of remarks that DS, when he's older, will start to pick up on them.
Other gems include calling the Chinese person next door a "cufflink"
. Should I say something, or just let it go?