On Monday afternoon Khloe Kardashian and rumored boyfriend Matt Kemp hit the gym in Beverly Hills, and while they left separately, they were definitely there sweating it out at the same time!

Matt later headed to a medical center nearby, and it's being reported that the MLB star will be joining Khloe and the rest of her family later tonight for a big bash at casa de Kardashian. Kemp, along with 200 other guests will be at the party, according to Radar.

Dont expect Khloe and Matt to be huddled in a corner off by themselves as they know people are talking about them this point, they are taking things very slow," a source for the website dished. "Khloe is still extremely sad about the end of her marriage to Lamar Odom, but she had moved on several months ago.

I mean, he DID Instagram a photo of the Kardashian family's Christmas tree the other day, but until we see a pic of Khloe kissing him, we're not sure that we believe they're an item...