To borrow from what Tasha said, Lawrence isn't really a horrible dude per se, but he's definitely in a fukk nikka phase. He just got out of a five-year relationship that ended with him getting cheated on and prior to that, he legit wasn't doing anything productive.
But I'm not surprised that he got past that argument quickly. Yeah, he lost out on consistent box (and a dude would care about that to some degree), but what this show seems to be leading toward is that Lawrence on the surface is going to look like one hell of a catch (job, objectively handsome, in shape, etc.), and that waitress let him know it too. The question is whether or not he's gonna choose to be savage or will his own shyt get in the way, and then we'll really see if he's a fukk nikka and not just a dude letting his fukk nikka tendencies win right now.
After all, they weren't doing anything but fukking in his mind. For him to dwell on that any further would have made it into something more. That said, it was on him to examine the behaviors he was showing and ask whether or not it would affect how Tasha saw things. He told her about Issa when he had no reason whatsoever to do so because they weren't exclusive. He agreed to go to that cookout and meet her folks when she said he didn't have to go, knowing that most of the time, meeting the folks means this is going somewhere long-term.
Yeah, she messed up when she tried to escalate it in order to see exactly where he thought it was between them.
On the other hand, she gave him a chance to show that it was exactly what she thought it was, and he chose to show her something different.
Still, people will get away with what they are allowed to get away with.