Grey's Anatomy and Private Practice spoilers don't always intertwine, but tonight, when the characters from both are on screen (and hooking up) with each other, they do!

Below are a couple of excerpts from EW's spoiler Q&A this morning.

We suggest if you are looking to keep the events of this evening a surprise, particularly involving the romantic dalliances of Dr. McSteamy, you not read past the picture ...

The last such moment we may see for awhile.

• Things will heat up between Sam and Addison on Private Practice. Starting this evening, when he gets jealous of Mark, and again in February.
• Their guilty consciences will prove a major obstacle, however, as will the added complication involving another doctor waiting in the wings!
• Mark and Lexie are over. Done. The lovers will break things off this week, but their single status doesn’t really become official 'til next week.
• That's when word of their respective dalliances comes to light. Interestingly, someone’s reportedly not as upset by this as you might think.
• Katherine Heigl returns to the set in late February, so Izzie should likely be back on a regular basis in episodes airing in March or April.

Thoughts? Theories? Opinions? Who is the other doctor waiting in the wings for Sam or Addison? Is Mark not the only one doing the cheating on Lexie?

Steve Marsi is the Managing Editor of TV Fanatic. Follow him on Google+ or email him here.