I have had this problem for a while, now and again whilst gaming online i get lag spikes which make it near impossible to enjoy playing online. I have a very good package with good download speeds, i am gaming off a wireless connection but that shouldnt be the problem, when there is no lag spikes my connection is perfect but would like to know why i get them, thanks.
You'll both need to do some isolation tests. Get your consoles and run ethernet cables to them (during times where you experience poor ping) (write down values before and after if you can) and verify that this fixes the issue.
If thats the case, it is your wifi not VM. If it remains it is VM.
If it is the wifi in the end, I suggest you download Wifi Analyser app and check the spectrum in your area and see if you can move to a less congested channel.