As he turned the corner to walk down another hallway he spied them – heads together and fingers entwined- and he had to duck into an alcove to compose himself. Seeing a head of dark messy black hair so close to a redhead brought back in full force the feelings of abandonment and betrayal from his seventh year- a reminder of his unrequited true love. Feelings that he definitely did not need this year of all years because of Dumbledore and his demands. Why bloody Potter had to go and find himself a redhead and follow in his father's footsteps was beyond him. Could this all be about him? Was this another form of torture that another Gryffindor had come to give him, just like his school days? But no, Potter could never know his true intentions and the real reason why he always came to Potter's rescue. Even after sneaking in to the pensieve last year and seeing his worst memory, Potter thought that it was all about the bloody Marauders instead of the real reason why that was his worst memory- the idiotic word that slipped off of his tongue and ruined his chances at happiness.
After catching his breath, he came out of the alcove and looked down the corridor, pleased to see that the couple were out of his sight. As he swept down the hallway, he thought that it was much easier to accept that Potter had a love-life without the evidence of said love staring him in the face. Maybe it was a blessing having Harry Potter and Ginny Weasley become a couple at this moment. Maybe this was the strength and resolve he needed- to be reminded that he did this for his love, for his Lily. He would kill his mentor for her, even though she chose another man, because this was the plan to ultimately save the wizarding world- even if he could not save her son in the process.
With that resolve in mind, Severus billowed down toward the dungeons and toward another classroom full of dunderheads.