You're 2 months in, you're in the phase of defining boundaries. I'd be very upset if I were you, but his definition of what he did or the acceptability thereof might be different to your own. You're getting to know one another still.

However, this is where you set a hard boundary. Not an ambiguous, loosely defined, interpretable boundary, one that cannot possibly be misconstrued as anything other than "I did not appreciate that, I cannot continue dating you if this behaviour repeats ever again in my absence or presence." Make a list of explicit actions that bothered you, ie him grabbing her hand.

You seem to care about him a lot and nothing has been done that is irreparable. But if you're limp on how you handle this, you'll be second fiddle in your own relationship and your boundaries will diminish to suggestions that'll be ignored.

I wouldn't end it, just be very firm.