It looks like there's a good reason why Katie Holmes and Jamie Foxx have been keeping their relationship on the down low—they are supposedly scared of Tom Cruise's reaction to the two of them dating.

According to Hollywood Life on Wednesday, both Katie and Jamie are worried that Tom might "go crazy" if he finds out that his ex-wife and former friends are planning to make things official. Tom went on a bizarre media blitz back in 2006 when he declared his love for then-wife Katie by jumping on the couch during an appearance on Oprah Winfrey's talk show.

Now, Katie is worried that Tom might go nuts again—and this time around it might be even orse.

One source even said, "Jamie loves Katie so much and he prides himself on keeping his relationship with her private."

The insider added, "That said, if and when he does go there and put a ring on her finger, he's not going to do it publicly. The last thing he wants is Tom going all 'Collateral' on him. Jamie doesn't know Tom's crazy side and he likes to keep it that way. He's heard war stories from Katie about what it's like to be his bad side and he doesn't want that drama."

So far, neither Katie nor Jamie have said anything about the wedding plans, but then again they haven't even publicly acknowledged that they've been dating for the several last years, too.

Keep up with Enstars for all the latest news on Katie Holmes, Jamie Foxx and all of your favorite celebrity couples right here.

Tags: katie holmes