Looking on the internet deeply has found these results:

at the center of our friendship is the most popular phrase on the web.

in the center of our friendship 10 results on the web	at the center of our friendship 188 results on the web More popular!
Some examples and use cases from the internet:	Some examples and use cases from the internet:
It doesn't look like this phrase is very popular! The search could not find any examples on the internet.	Once in awhile there were tears; someone would leave in a rage, we would argue but interest in the art of writing was at the center of our friendship. … Continue ... May 25, 2015 ... She's the warmest most empowering most loving person I know. ...At the center of our friendship is radical vulnerability, and I feel so lucky to be ... Jun 19, 2012 ... ... Anthologist staff meetings—that's the Rutgers College poetry magazine—so books were at the center of our friendship from the beginning. Aug 9, 2013 ... ... Anthologist staff meetings—that's the Rutgers College poetry magazine—so books were at the center of our friendship from the beginning.

in the center of our friendship

10 results on the web

at the center of our friendship

188 results on the web

More popular!

It doesn't look like this phrase is very popular! The search could not find any examples on the internet.

Once in awhile there were tears; someone would leave in a rage, we would argue but interest in the art of writing was at the center of our friendship. … Continue ...
May 25, 2015 ... She's the warmest most empowering most loving person I know. ...At the center of our friendship is radical vulnerability, and I feel so lucky to be ...
Jun 19, 2012 ... ... Anthologist staff meetings—that's the Rutgers College poetry magazine—so books were at the center of our friendship from the beginning.
Aug 9, 2013 ... ... Anthologist staff meetings—that's the Rutgers College poetry magazine—so books were at the center of our friendship from the beginning.