That
appears
to
be
Kris'
way
of
thinking
as
she
headed
to
image-sharing
website
Instagram
on
Saturday
afternoon
to
show
off
a
picture
of
Bieber
and
Kourtney
Kardashian's
five-year-old
son
Mason
Disick
having
fun
in
the
pool.
"#Mason
&
@JustinBieber
family
pool
day!!!
#Bestbabysitterintheworld
(sic)," Kris
captioned
the
image.
Bieber
himself
didn't
seem
to
hate
his
afternoon
with
Kourtney's
oldest
son
either.
Wearing
a
baseball
cap
and
his
signature
shades,
the
crooner
wrote:
"Mason
is
cool
as
a
fan."
The
Kardashian
family
and
Bieber
have
a
long
history
and
friendship
together.
For
a
time,
Kourtney
was
neighbours
with
the
pop
star.
There's
also
a
special
bond
that
Kendall
Jenner
and
Kylie
Jenner
share
with
the
singer.
Whether
posing
in
photoshoots
together
or
hanging
out
together
at
mutual
friends'
parties,
the
threesome
have
remained
friendly
for
many
years.