Not very useful for aikido though. Especially since whenever I ask him how to do this and that his only response is "get better"
I never ever get a chance to finish a technique because he knows how to kaishi waza out of it, so I never know if I'm getting better or not.
i think that this is the punch line of your story.
if your "senpai"/"friend" is only keen on showing off and not allowing you a chance to train or improve, then, the rest of the discussion is moot. even if he was O'Sensei reincarnated and had the skills of Bruce Lee with the powers of Anakin Skywalker--if he's not helping you learn anything aside from putting you down and chasing skirts, then you might learn more training with a mediocre aikidoka who actually cares and is interested to help you learn to your highest capacity. IMHO anyway.