If someone can offer a better translation, go ahead.
This seems to be based on "reverse chocolate", an initiative in Japan to make men give out chocolates on Valentine's Day, as opposed to traditionally on White Day a month later. Don't know if it's general knowledge.
I think all these pairings work for each other Red x Yellow = At the end of the Yellow Arc of the manga she saw a red ribbon that connected her pinky to his implying love between the two Ruby x Sapphire = She tells him she liks him! What else is there to say about the two?! Heheh those are my fave pairs.