Silences or not, Snape's eyes flash with unadulterated hatred as Sirius dares to take what was both hard won and freely given to him. His hand is up, wand pointed again, uneven teeth ground.

But Andromeda is buying Sirius time to prove he can be the better man as Snape fights the charm, breathing still labored and harsh. His eyes flick to Andromeda as she addresses him, and he drops the wand a fraction of the inch, but manages a voiceless snarl in Sirius' direction. He will not let that man treat him like this, not after so much at the hands of these tormenters.

Of course, he's just tossed a couple of days of healing right out the window... much like how his good intentions sent them out there afterwards, to help the man.

Next time, he'll just let Sirius risk splattering himself on someone's window. Will serve him right.