Are there any negative consequences associated with asking your former advisor about the status of a joint paper collaboration? I coauthored a paper with my former advisor and he sent it to an expert for review before submitting it to a journal. A couple of weeks have passed by and I would like to know the status, but I have not heard anything new from my former advisor about the paper.

I thus am wondering: 


  Are there any negative consequences associated with asking my former advisor about the status of the paper? 


Simply put, I am afraid that my former advisor would feel that I am being pushy or something similar. 

Moreover, if there are no negative consequences, I would like to know how to properly formulate such an email.
I see no problem with such a question.  Just phrase it in a non-pushy way, like: 


  Hi, XXX: I just wanted to check in on the status of our paper, since we sent it to YYY for input a couple of weeks ago.  Do you know if YYY has gotten a chance to review it yet?