I know... during the AO we should be damn serious and not talking about gossips... but you know human nature...
I found it quite telling this interview reported by a couple of sources. (it's the same).
Sharapova seems to be embarrassed and she does not deny the relationship...
So, if she react like this....It might be true.
ps. By the way, Dimitrov would be better to focus a bit more on his tennis results especially after losing to Benneteau (his tennis was so poor).