The 7th house is the house of marriage, partnership, and physical intimacy. Ketu is the planet of detachment, separation, and wandering.
When Ketu sits in the 7th house, Dr. Sharma explains that it creates a constant, underlying "sourness" ("khattaas") in the marriage. There may not be massive fights, but there is a deep lack of emotional and physical connection.
The most prominent *Nishaniya* (symptom) of this placement is avoidance. The person will constantly find excuses to stay away from their spouse. Instead of spending time at home, they will run outside to spend time with friends or wander aimlessly ("doston ki taraf daudta hai").