At first he had considered proposing to her in the game room, but had ultimately decided the formal living room was more appropriate. The intimacy of the game room would have most likely scared Lasha. And Stefan knows she needs to be as relaxed as possible to truly listen to his speech, to truly consider his proposal. If she is frightened or intimidated, she would run. As she had done more times than he could count.
Defeat is unacceptable.
The door bell chimes telling Stefan the time has come.