According to Damon Knight in The Futurians:
The Futurians were apparently not much impressed by Asimov at this time. Pohl remembers him as small, skinny and pimpled, and says that his conversation did not sparkle; he seemed to have absorned a lot of information without thinking much about it. Wollheim says that later on, when he came to visit the Futurians, he often had to be ejected because he was noisy.
"After about half an hour we couldn't take him. Diry [Harry Dockweiler] and myself, or Dick Wilson and Bob Lowndes would simply take him and heave him through the door. We couldn't stand him, you know. You can't really offend Ike, he always came back.*
Knight then said in a footnote:
Asimov does not remember this, and thinks it is not the sort of thing he would be likely to forget. He does remember a time when he brought his sister Minnie over and the Futurians, for a joke, pulled her inside and closed the door, leaving Asimov in the hall. "I got very panicky," he told me. "I had some vague notion that they might do something to her, and I'd never be able to explain it to my parents. And I remember banging at the door very hard, and finally they let me in."