Kylie Jenner did a good job of acting coy -- but she also made sure to show off the blinging engagement ring while hanging out with her rumored fiance Tyga on Thursday night in Calabasas, Calif.

Kylie looked casual in a 424 University Hoodie, which costs $235. Tyga wore a black Ferrari shirt and a black ball cap for their low-key hang.

The twosome seemed happy to hang out together without all the glitz and glamour, which may have to do with Tyga's recent money troubles -- he had to shell out $480K last week for owing his old landlord back money in rent and for damages. This week it turns out that a Beverly Hills jeweler is alleging that the rapper owes him $200K for not paying him money owed for a watch and gold chain necklace.

Maybe Tyga should be eating ramen and taking the bus given his financial issues!

When asked last month by Hollywood Today Live if he's proposed to his 19-year-old girlfriend, the rapper has previously been rather evasive, saying, "I don’t wanna give it away."

Umm ... whatever that means! That ring kind of gives it all away!