Tyga really knows how to prove his commitment to Kylie Jenner and her family. Step one: Sign to Kanye West's record label . Step two: Buy her a promise ring stacked with a diamond that could sink an ocean liner. Kris Jenner couldn't have planned it better.The 19-year-old Jenner showed off her bling on Snapchat yesterday, after debuting it while attending NYLON magazine's party at Provocateur in downtown Manhattan on September 8. After a lengthy story that includes her elevator mishap , the reality star slipped in a shot of her ring, her hand lovingly placed on Tyga's thigh."If this is my promise ring, I wanna know what my engagement ring is gonna look like," she captioned the shot.At this rate, it'll probably block out the sun. Of course, given Tyga's recent legal trouble with jewelers claiming he still owes them money, she might want to manage her expectations. At the very least, get a receipt!