The Tottenham goalkeeper was pictured all smiles with his arm around a team-mate.
The beauty of the Tottenham Hotspur squad right now is that everyone seems to get on like a house on fire.
Morale is high at White Hart Lane and it usually is when a side is in the kind of form the north London club are in.
Indeed, ahead of Spurs' visit to West Ham United, Son and Lloris looked like best friends as they joked during training.
Son came to Tottenham last summer and has played an important yet lower-profile part in recent weeks, while plenty of his team-mates have spoken highly of the forward since his arrival.
Meanwhile, Tottenham's full-backs were also in high spirits on Monday afternoon, with hero-of-the-hour Danny Rose pictured smiling alongside Kyle Walker.
Ben Davies and Kieran Trippier were on show, too, looking focused: