I recall the CRM class where we were asked to do a Checklist on relations in the company.

There was an item which asked for "I have colleagues who are friends".
Instructor said if we dont check this, it spells trouble.

I don't agree.

I may have mentioned not less than umpteenth times to friends to you to everyone to my blog that Friends and Colleagues constitute different definitions. Both enjoy different priviledges.
It's hard for me to mix. I keep a distance with Colleagues. purposely.

I am patient with colleagues but stern when a job's not done.

I am impatient with friends, but accepting when conflicts arise.

The above is of course non-exhaustive.