Jon Hamm and his girlfriend Jennifer Westfeldt were reportedly robbed during a trip to London.

The Hollywood stars were in the UK to promote their new movie Friends With Kids earlier this month. They were dining at a restaurant when Jennifer's handbag was snatched.

The writer-and-director's bag contained their hotel key, which led the thief to their accommodation and enabled them to clear out their room.

"What a mess," Jennifer told Life & Style at Tropfest New York. "[I'm not feeling] great. It is under investigation."

But the 42-year-old added that she is happier than ever with her Mad Men beau.

The actress has been with Jon since 1997 and explained that working together on Friends With Kids has brought them even closer.

"Some people would say they could never work with their partner, but we found it incredibly bonding," she said. "Independent films are so stressful; it feels like pushing a boulder up a hill. So it felt great to have a partner in crime."