Despite insisting last month that they're just friends, Scarlett Johansson and Sean Penn continue to set tongues wagging that there may be just a little bit more going on. Tuesday morning, they took a private jet to Cabo San Lucas, Mexico, where they were seen having lobster and margaritas, People reports. They were back in California by early yesterday. Penn, 50, and Johansson, 26, were also spotted earlier this week having a very friendly-looking lunch—ScarJo had her leg in Penn's lap. Click to see another Hollywood A-lister recently linked to Johansson.