Possible Clues:

• One involved in two matches at the same time
• One who unlawfully marries a second wife
• Mr. with the Mrs. and Mrs.
• Lawbreaker with two partners
• However thick a fog, he will mate in two
• He won't introduce his mates to each other
• Person who commits crime of marrying while still married to another
• Perhaps FOG with wives
• One with a spouse too many
• It takes a peasouper, perhaps, to mate in two