I just did a quick search on this and it doesn't look like it is a sauce, it looks like it is a marinade. The meat does not absorb that much, and the nutritional info I read had 0-3G of sugar. It may not be as much as you think. The butter won't put you out either. I think you are ok.

if you want to be sure you could always pick up some ketostix.
It's ok, just remember the nice time that you had with your hubby, not what you ate.