Dear LamBa readers: My brother is still friends with my ex, is it right?

From a female LamBa city readers
I dated one of my brother's best
friends for a year and two months
and broke up with him just last
November. My ex has moved on and so
have I but what pisses me off right
now is that my brother is still friends
with this dude. I'm angry at that
because our relationship ended because
his friend cheated on me with

someone in our inner circle. I expected
my brother to at least have my back
and be on my side on this one but
he's still hanging out with my ex and
even going out with him and his new
girlfriend (not the girl he cheated on
me with). I confronted him some days
ago and he said what we had was
between us and he never got involved
and their friendship is between them
and I shouldn't get involved. I'm
currently not on speaking terms with
my brother because I feel betrayed by
him. I was hurt by his friend and he
would continue to be friends with
him? Where's the loyalty? I've cut
him out of my life until he cuts his
friend out of his life. My brother is
wrong for still being friends with a
man that hurt his baby sister, is he
not?