In an attempt to escape unwanted attention, the pair get out of sight... by checking into a love hotel.
This is actually a chance for Miia to bemoan how scary she appears to humans.
Then the interspecies enforcement squad arrives to make sure they're not breaking any laws.
As they retreat, they are met with more mockery, and Miia gets mad. Kurusu determines that while the Prohibited Matters will get her in trouble if she overreacts, there's no law against _him_ punching that asshole in the face.
(I am not a lawyer, this is not legal advice.)