Ed Westwick on Vacation In Mexico With Girlfriend

Ed Westwick and his girlfriend, Jessica Serfaty, hit the surf in Tulum Tuesday, but it didn't help cool off their hot makeout session in the water.

If he's still worried about his legal troubles back at home, he sure didn't show it. As we previously reported ... Westwick is being investigated by the LAPD after several women came forward and accused him of sexual assault. Serfaty has stood by his side through it all.

In Tulum, she was actually not only by his side, but also on his back and straddling him in the water. She also put Ed to work.