100 years ago when human still live in small village and everybody knew each other, maybe yes. But now, human live in dark age when one will do anything to win against the other from good sportsmanship even dirty trick that will end with one side lost something they love. So, i think its impossible to give somebody our trust even somebody that we think really close to us, there still chance for them to back stab you.
for you who too lazy to read, the simple answer is no
p.s srry if some of my grammar went wrong, English is not my first language