Maybe it would be better to tell your wife that you interpreted her complaint as having sole custody of the kids which conflicts with the joint custody that was discussed. Hear what she has to say in response, say nothing yourself and leave it at that. No 'what you're doing' or when, how, why.

Would that work for you?

Me: 31, W: 29
T: 4 M: 2
Kids: 3 (SS: 7, SD: 4, D: 3)
Separated, still living together: Nov 2013
Separate bedrooms: Feb 2014
W working away; kids with me: Nov 2014