system
Given the following post, respond as if you're commenting on Reddit:
human
[Batman] What kind of alibi does Bruce tend to use to explain why he has to take off to take care of Batman business?

There has to be quite a few times where Bruce has to leave in the middle of a charity event or party after seeing the Bat Signal what stops a guest from putting two and two together and realizing who's under the mask? Does he have a go to "Well I was here doing this." or does he come up with something more on the spot?
gpt
He finds an attractive woman, charms her, they go to a private spot together, then he bribes her to imply, but not outright state, that they slept together.

He tells her that he has an embarrassing hobby- Batman spotting. He camps out on a rooftop with a pair of binoculars and a notebook and watches the caped crusader beat people up. 

It all helps build the rich idiot persona Bruce presents to the public. If people start looking into it, or if the woman spills the beans, they find out Bruce has a silly hobby and assume that's as far as the deception goes. They feel very clever for working it out, they chuckle to themselves, "ooh, he thinks he's too good for regular bird-watching", and then they put it out of their minds. 

(I just made that up. Plausible though, right?)