CHILF means you are child and dilf at the same time, Child I'd Like To Fuck but in this case it just means you're a Future DILF. also it means dilf who is younger than you. (it's not illegal)
The children of a chosen Milf and Dilf, sent by Lil Nax(sty eggs). Therefore, the chilfs of their time.
"Man, look at those siblings. They're insanely hot and smexy."
"Yeah, they're mom is a milf and dad is a dilf. "
"SHEEEEEEEEEEEEEEEEEEEEEESH, they chilfs"