They're not big on PDAs. Well, Kate isn't. Though she's pretty sure that Clint could easily be talked into having sex in the middle of the street, with just a little coaxing.
Fortunately for them (and for Cap, whom Kate is sure doesn't want to receive the call to come bail them out of jail for public indecency) exhibitionism isn't Kate's kink. That she's aware of. She's still working on figuring out which kinks she has, but she's pretty sure she can scratch that one off the list.
Mostly, she likes keeping what they have private. Those early morning kisses over purple coffee cups, late night archery competitions, and mid-afternoon showers... all of those are things Kate enjoys with Clint, and none of them are anything that need to be shared with anyone, be they supervillains on patrol or the average New Yorker out on a stroll.
But as they sit on the bench in the park and wait for Arrow to finish his very important business of chasing pigeons, Clint's hand manages to wrap around hers.
Kate gives it a reflexive squeeze, and to her surprise, finds that hand-holding is the display of affection she doesn't mind making public.