Why do people blame abuse survivors?

I live in an apartment with my husband and 2 children (3 and 5). My upstairs neighbors are very very nice, in their mid 20’s with no children.
Unfortunately I have noticed that you can hear them from my sons’s bedroom and can hear them being intimate.
They aren’t screaming or being obnoxious at all but you can still hear the faint moaning/breathing. My sons have noticed and are asking what it is.. Even imitated the noises at daycare..

I don’t want to get anyone into trouble with the apartment manager or embarrass anyone, but I don’t know what to do?

Updates
17 d
EDIT: Yes I’m aware of the title glitch. I do apologize
Why do people blame abuse survivors?
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