I think the younger man in the left foreground is making the kissy face at whoever is photographing this.
The older man in the background (his father?) has noticed it and looks like he's thinking "WTF is <name> doing?" and he probably said something like that next, e.g., "<Name>, what the HELL are you doing? Do you want to kiss <photographer's name>?"
The woman mostly obscured by the younger man is smiling, so she hasn't seen this or doesn't care.
