Perhaps your sister is saying that if you mess up with his sister her husband will talk to her about it and would be all over you. Perhaps she doesn't want her husband to have to punk you out. And even if you are a "good" man, she still won't have to worry about anything involving that.
The cast of Husbands Are So Jealous - 1934 includes: Jack Livesey as The Husband
The Man Who Made Husbands Jealous was created in 1994.
Miracle of the Jealous Husband was created in 1511.
Hera
The cast of The Jealous Husband - 1910 includes: Fred Rains as Husband
The Man Who Made Husbands Jealous - 1997 is rated/received certificates of: UK:15 (DVD/VHS release)
Jealous Husband - 1908 was released on: USA: March 1908
She is jealous probly because she still likes him and she is mad that he already moved on and married
A Jealous Husband - 1913 was released on: USA: 3 June 1913
A Jealous Husband - 1914 was released on: USA: 18 June 1914
The cast of A Jealous Husband - 1914 includes: Ford Sterling
It is normal behavior...Do not feel jealous of your husband. Make a healthy relation with husband and talk freely. Try to understand what is like and dislike of your husband and try to satisfy him.