Uh. It's called not visiting.
There is a story told over about Rav Ahron Kotler zt"l.
Rav Ahron was known to yell at bochurim who asked questions in middle of shiur. He loved every bochur, and his yelling was pure rischa d'Oraysa, but the better the question, the more he would yell.
The rosh yeshiva did allow people to ask questions in middle of shiur, but you had to be prepared to get yelled at. The general rule was that the better the question was, the more you got yelled at. He would say, ‘Am ha’aretz,’ ‘Am ha’aeretz m’doreisa,’ and other such expressions that he was known to say. But if someone asked a question that was based on a mistake, or something that didn’t make sense, he didn’t answer, but he would just continue giving shiur.
(Nowadays, it’s difficult for us to understand how a rebbi would talk that way to a talmid, but in previous generations, bochurim understood that being called an am ha’aretz was not meant to insult the bochur, but rather it was a message from their rosh yeshiva to think harder and shteig, and that they were capable of doing that. So in a sense, the rosh yeshiva was praising the bochur.)
A story is told that a bochur once asked a kasha in middle of shiur, and Rav Ahron started yelling at him, expressing how the question is a mistake and that he does not understand the true meaning of the gemara. After going on for a short while, the bochur slipped out of shiur, but Rav Ahron didn't realize, so he continued. After a minute, Rav Ahron shouted, "send that bochur out!" When the other bochurim said that the bochur had already left, Rav Ahron said, "Ruf em tzurick un shik em arois nochamal - call him back, and send him out again!"
