What if Sirius took Remus on holiday to propose.
Remus: Sirius where are you taking me??
Sirius: can't tell you but I know you're going to like it. (Kisses Remus softly and Remus obviously kissed back passionately.)
When they pull away Sirius grabs Remus' hand and apparates them to... HAWAII!!
When they get to their holiday cabin Sirius pushes Remus softly to the sofa and lays him down underneath him. Sirius puts his hands on Remus' hips and kisses him.
They pull away after what feels like forever. Renus is pulled into the bedroom by Sirius and is told to change because Sirius is taking him out for dinner.
2 hours later they have eaten so Sirius decides to propose now.
Sirius: (takes a deep breath abd kneels down) Remus John Lupin I have loved you since forever. Will you marry me?
Remus: (is sobbing his heart out) of course Pads I love you.
2 weeks later they got married and 1 month later Jily were murdered by Lord Voldemort!