I was flying from DEL to EWR in C+ aisle . A woman was sitting in the middle seat. The husband was siting in the second seat next to a female with six across. Told me I had to switch, because a man cannot sit next to married female. I said no. I then stated have the wife sit next to the female, and you take the middle seat. The woman started coughing very loudly. He got the female who had the window seat to move. She sat next to me the whole flight.