Ben Affleck knows boundaries, and when others don't he clearly takes charge, especially in the presence of his GF.
Ben and J Lo were at the Marco Polo International Airport in Venice when a hyper-determined fan zeroed in for a selfie. The fan got in their space and ... you never know someone's intentions when they cross the line, so Ben stepped in for the block.
J Lo's BF pushed the maskless guy away as she moved backward. It's interesting ... their bodyguard took over, wrangled the guy and continued to push him away from Ben and Jen. So, Ben didn't wait for his hired muscle ... he took care of business himself.