From the Men in Black autopsy scene:
After a particularly gross GUSHY sound, he looks away, toward her. She's staring at him.
Laurel leans over and lowers her voice, just for him.
LAUREL You know what I like to do sometimes? When it's really late? JAY (freaked out) No...
And, as far as I know, it's never mentioned again. I'm curious if we know what it is she likes to do.
I've always assumed it was left intentionally unaddressed, because, well, that's funny. But I could have missed something. Plus there is the MIB comic. Figured I'd ask.