Chyna and Rob sitting in a tree, K-I-S-S-I-N-G, first comes love, then comes an engagement ring, maybe? Rumor has it, that the Blac Chyna-Rob Kardashian love affair may be getting a lot more serious.

According to Cosmopolitian, Chyna recently posted an Instragram photo where it is easy to spot a huge diamond ring on her 4th finger, left hand.

The picture was taken at this year's Trinidad and Tobago Carnival along side Chyna's BFF, Amber Rose, and a few other close friends.

Now we don't know for sure if this is an engagement ring, a promise ring, or a really expensive piece of jewelry that the star decided to put on display.

However, Cosmopolitan says, the star posted a very mysterious Instagram video with a ring emoji as the caption.

Is Chyna hinting something? We're not quite sure, but we are sure that Rob has serious eyes for Chyna, according to a source from People.com.

"Rob has fallen hard for Blac Chyna. She makes him super happy and this is the first time that he's felt so optimistic about life in years", say the source.

The source also says that 27-year-old Chyna has been a positive influence in Rob's life, after the reality star battled with depression and weight gain over the last two years.

Since she revealed their relationship on January 25, Chyna has never been afraid to post her intimate photos with Kardashian.

US Weekly says, Chyna posted another instagram photo with Rob's hand gripping her backside, with the caption "Missing Bae," featuring the diamond ring emoji once again.

Whether or not the engagement is a rumor, the two seem to have genuine feelings for one another. Blac Chyna may just be the key to getting Rob back to his old self again.