I think it has been made clear that Ezra and Aria have indeed been intimate, even though not in any graphic fashion.

The writers of this show are really going against convention by showing this relationship between Ezra and Aria develop, and having an intergenerational relationship where the older male participant is a basically good-hearted guy like Ezra who clearly cares about Aria, and in no way depicting Aria as a naive victim but simply as a girl in love, and playing a classic role in fighting societal norms to have the relationship she wants. Being a hebephile, I completely understand how they both feel for having to keep their relationship secret, and the stresses Aria suffered as a result, even though I do not condone illegal relationships nor engage in them myself. It was very big of Ezra to take the risk of coming clean to her parents like he did. This show has earned my respect for its very bold and unconventional depiction of an intergenerational relationship, with neither the older male nor younger girl participant in any way fitting the common stereotypes attributed to each by the media.

And it was kind of Mike for punching Ezra to prevent Mr. Montgomery from feeling the need to do so himself...evidently, Mike realized he couldn't punch nearly as hard as his dad.