well some friends are not really trusted that much by me so i would not want such friend to date my sister because even i myself do not trust the friend that much and i do not know what he is capable of doing to my sister,i would not want my sister to get hurt so i have to be careful,but i have a friend that i trust so much and i love his way of life,i can allow such friend to date my sister and i will gladly endorse the relationship..