Soo... Basically Ukraine isn't allowed to have a relationship with the United States because it would make russia, the jealous ex, jealous? Pardon the analogies, but that sounds like the same argument one would use to explain that women wouldn't get sexually assaulted if they didn't dress so scantily. It's preposterous.

It's not surprising. Both Mearsheimer and Putin both subscribe to the theory of offensive realism, while most Western cultures lean more towards defensive realism.