Married too long

This wife buys a pair of crotchless panties in an attempt to spice up a dead sex-life.
She puts them on, together with a short skirt and sits on the sofa opposite her husband.
At strategic moments she crosses her legs ……. enough times till her husband says
”Are you wearing crotchless panties?”
“Yes,” she answers, seductively.
“Thank goodness for that. I thought the stuffing was coming out of the sofa.”