This is "Marriage A-la-Mode: 2, The Tête à Tête" by William Hogarth. Painted in the mid-18th century, this work is a scathing critique of the upper classes in England at that time. It's part of Hogarth's series on Marriage A-la-Mode, which was meant to be engraved and sold separately.
The scene depicts a few months after the wedding of the Earl of Squander's son to the Alderman's daughter. The bride looks sleepily exhausted, likely from a late night of playing cards, while her husband sprawls in his chair, worn out from his own nocturnal exploits. A small dog tugs on a girl's muslin cap from his pocket, and another cap is wrapped around the hilt of his broken sword.
The Viscountess seems to be holding court, but not with her husband. The overturned chair and fiddle cases suggest she's been indulging in more intimate activities than just playing whist. A man's head carved on the mantelpiece hints at a possible third party involved in this tête à tête.
Marriage A-la-Mode: 2, The Tête à Tête hangs in The National Gallery on Trafalgar Square, London — free to enter. Point your phone at any artwork there and audioguide.london plays a free audio guide in six languages — no app download needed.