This is a tough question - but here goes.

There are two kinds of boiled peanut eaters.

The first kind crack the hull with their fingers and then suck the salt water out and pick the peanut from the hull.

The second kind place the peanut, hull & all, into their mouth to suck the salt water out. They then either crack the hull with their teeth to remove the peanuts or they crack the hull with their fingers then remove the peanuts.

Either method is socially acceptable – as long as you do not eat the hull.