The $450,000 Lamborghini given to Kylie Jenner for her 18th birthday by rap star boyfriend Tyga is reported to actually be a vehicle leased in her name.

"He leased it," a source told Radar Online of the "Rack City" rapper. "He couldn't afford to actually buy one for her."

The website adds the fact that Tyga couldn't afford such an extravagant expenditure is yet another example of why her family members are so concerned about their growing relationship.

"Kylie's sisters and mom are worried that Tyga is trying to cash in on being with her," another source added. "She's young and they think she might not see what is going on."

Reports are the rapper has been enduring financial struggles for some time now and was recently ordered to pay $70,000 in back rent and to vacate a house in Calabasas, California. Tyga has claimed that he was no longer renting the home and was in the process of purchasing it outright.

Jenner and her 25-year-old boyfriend star together in his latest video "Stimulate," where they pack on mounds and mounds of PDA. In one verse, Tyga makes graphic reference to what many perceive to be intimate details of the couple's relationship with the line, "She a big girl, dog. F*ck what they talkin' about, n*gg*. She a big girl, dog. I'm gonna do what the f*ck I wanna do when I wanna do. She a big girl, dog. I'm puttin' in, I'm penetratin. I'm gettin' big, I'm stimulated."

Recent reports have also suggested the pair was considering eloping after she became 18 and were even contemplating moving away from L.A. to either New York City or Europe to escape all the drama they are often engulfed by.