I liked this comic, a lot, for a simple reason: it shows an assertive, confident side of Clinton, that makes me think he's definitely on the right path - even if it manifests through anger.
Previously, Clinton was either the gushing Hannelore fanboy, or the immature guy ready to do anything to impress a woman (the haircut / power plug tatoo comic was both hilarious and sad at the same time). We've rarely seen him stand up for himself and take control of his own life.
Here, it's exactly what he does. He's calling his sister on her bullshit; he's demanding respect, maybe for the first time; he defines what is acceptable to him and what isn't. And that's wonderful - that's so much more mature than the Clinton we know. He's growing, he's definitely growing and learning; and even though things are not working out with Emily, he'll overcome it, and have more success in the future.
As for Claire, I'm not worried about her. She'll have a good cry in Marten's arms, and be fine. And I'm pretty sure that Marten, while laughing about the situation, will confirm - in a nice, gentle way - that what she did was not okay, and she'll think about it, and will eventually grow as a person too. Everybody grows!
The kicker is that I'm certain that Emily meant exactly what she said by "I just don't have time for dates", and that it wasn't a rejection aimed at Clinton particularly. It makes perfect sense in Emily-logic!