I've NC'd for this.
I work in a small team of two in an open planned office, with our boss working in a different location.
In the past few months I've noticed my colleague spending a lot of time doing non-work activities on their (work) computer; things like online shopping / personal photo editing / news reading.
I'm not sure if this has gone unnoticed by my boss. We rarely share deadlines, but I have noticed these being missed. Delays are often blamed on other people within the business.
The lack of work doesn't really impact on my role, which is why I've kept my nose out thus far. However, its increasingly annoying watching the procrastination happen (often for most of the day), and then listening to the bullshit stories covering for it.
Whilst a few people in the office have noticed, they won't comment as separate teams - they're also my friends, so more likely to mention it to me!
WWYD? AIBU to mention it to my boss?