Sex joke «Another man...»

After a long night of making love, the young guy rolled over, pulled out a cigarette from his jeans and searched for his lighter.
Unable to find it, he asked the girl if she had one at hand.
"There might be some matches in the top drawer," she replied.
He opened the drawer of the bedside table and found a box of matches sitting neatly on top of a framed picture of another man.
Naturally, the guy began to worry.
"Is this your husband?" he inquired nervously.
"No, silly," she replied, snuggling up to him.
"Your boyfriend then?" he asked.
"No, not at all," she said, nibbling away at his ear.
"Well, who is he then?" demanded the bewildered guy.
Calmly, the girl replied, "That's me before the operation."