I ship Sneglus (Severus Snape x Regulus Black). And I wonder if someone ever asked Regulus "why?". Why does he continue to chase and pine over a man whose heart was given to someone else already? And I wonder if Regulus ever answered with an "I don't know either". And if he ever said "some things are just never meant to happen or last. No matter how much we long for it to."
And I wonder if, in another universe, Severus has obsessed with the idea of Lily being his only and true love when his heart began to beat for someone else.
If things would be so much different in a universe different from the one we happened upon where Severus loved another as truly as he loved Lily and Regulus lived.