OK, so for some reason Pintsize's behaviour genuinely upsets me in this context.
Yes, he's constantly doing stupid and annoying stuff, but usually he does that to people he knows and/or who are able to handle it. It's unclear how much he's deliberately making everyone angry because it's amusing, and how much he's mentally four years old, but his behaviour somehow... works in context. Wacky (and unfunny, but YMMV) hijinks, something happens to him in retaliation, move on.
In this situation, he's explicitly with someone who went on a date with him. The NATURE of interaction suggests a way to act. He's supposed to act in a way that makes the other side comfortable and, ideally, happy. Hanging out with someone... I dunno, I guess one could say he gets bored and starts acting stupid. Here, he's either being a dick to his date, or he's really *that* clueless and he thinks it's something he should be doing.
If he's being a dick, I subjectively think he's being a dick more than he usually is to people (and it's PINTSIZE we're talking about). The dialogue is really what pushes this into the "this is f-ed up" territory. He can't claim ignorance, because his date is OBVIOUSLY in "date mode" behaviour, and she's trying to steer him in that direction.
If he's being clueless, he obviously acts in a way that's inappropriate to people outside of the comic's main cast. So he's disruptive and annoying and potentially may do something actually bad. He needs help, whatever that would entail for an AI.
I genuinely can't put to words WHY this specific behaviour seems so much worse to me than what he usually does. He's done some pretty stupid things. I can't put my finger on it, but it's something about the situation, about the context that seems wrong. Maybe it's the fact that it's closer to real behaviour? I can't imagine a person gluing dicks to everything and ALWAYS making crude sex jokes (plus, it's hard to interpret that behaviour as anything but trying to be funny), but I can sort-of see someone doing something to interrupt every time another person says something. Sure, the stereotypical thing to do would be to make fart noises and not sling toast at them, but same difference.
His action, and this is the closest I guess I can get to pin-pointing why his behaviour seems wrong-er than usual, clearly states "you're talking, and I don't care. I'm not listening, and I'll show it in the most blatant way possible".
The fact that he's shooting the toast from his general crotch area doesn't help. Normally I'd say that's due to his chassis' height, but it's Pintsize we're talking about. That's probably a "sex thing" to him, everything is.
TL;DR - Pintsize is acting like a four-year-old here, but due to the circumstances it's worse, to me, than most things he's said and done.