Them continuing on with the rituals in the dark with a small lighter lit at the side, I'm guessing, signals that there will be light at the end of this long, struggling journey ahead for the two of them.
"Humare rishte ki shuruwat andhere se hui hai...par kya pata rishta jurte hi roshni aa jaye?"
Again, if I was the bride, I'd be like "Uhuh, what?" Like he's saying somewhat of a comforting statement to her, but in the coldest, most impassionate way ever!
"Jis ke chances zero hain", continues Abhi. Ohhh boy, you're not good at stats, lemme tell you that. Stop smirking!! Let me be a cheerful scrooge and take you two years into the future, where you're crazy about her!
AHHH!!! HER SUBTLE SHY SMILE IN RESPONSE + PUTTING THE GARLAND ON HIM + THE LIGHT COMING ON!! GO PRAGZ GO!