If a person or their expression is inscrutable, it is very hard to know what they are really thinking or what they mean.
In some circumstences, it is important to keep a straight face and remain inscrutable.
An inscrutable girl is one who'll make out, but not put out.
Mona and I got to third base, but she proved to be totally inscrutable.
The cunt that made Vince go through 5 long-ass areas and one drag-off of a bayou.
Fuck you Kosmo, you shrimp-dick.
Person 1: Oi who's that cunt 'ey?
Person 2: I think 'e calls 'imself "Kosmo the Inscrutable"
Person 1: What a fuckin' dropkick 'ey