Disclaimer: By now I'm sure you know what this means. But just know I made most of this story up. I usually only write about how it happened. But this is pure theory on lack of no looking anything up. Enjoy, though!
Lucius sat in the back of his potions classroom, the last class of the day before dinner. It was his seventh year at Hogwarts and he still felt like he never learnt anything accept how bad everyone thinks the unforgiveable curses were. As he sat there, he thought long and hard about the relationship he had formed with the dear Narcissa Black. He had grown accustomed to her. He didn't want to go as far as saying he couldn't live without her, but she did mean a dear lot to him.
The bell rang and the class shuffled out as Lucius slowly gathered his things.
"Is everything alright, Malfoy?" Came the voice of Professor Slughorn from behind his desk.
"Yes, sir. Just a little slow today is all." Lucius stated as he stood to leave, walking out the door, and making his way to the great hall for dinner. As he neared the entry way, he spotted Bellatrix walking toward him. She was the very attractive sister of his significant other, Narcissa. Their family had been close in ways of the Malfoy's. He knew he could trust Bellatrix, due to the fact that they were the closest to the dark Lord throughout the whole school.
"Bellatrix." He muttered as she was passing him.
"Oh hello Lucius. Coming to dinner?" she asked as she continued walking.
"Come here a second. I need to ask you something."
"What is it?" She asked as he pulled her to a nearby corner.
"What would you say if I…if I said I was planning on asking Narcissa to marry me?" He finally got it out, but it was no easy task. Sentiment never came kindly to Lucius. Bellatrix's eyes bugged out and she gasped for air.
"Lucius that's wonderful!"
"Yes but do you think she'll say yes?"
"Well," Bella started. She wasn't too sure of knowing because Narcissa never much talked about her love life with family. They always wanted her to find someone proper and rich and, of course, pure-blooded. But she knew her heart came first. "I do know she favors of you. But I don't think you have anything to lose. Go for it, Lucius." Bella said, smiling and patting him on the back gently as he walked away towards his meal.