Okay, so in sum, I think this is stupid because Peter has mostly been written out of being a dickhead who treats women badly, so this is bad (not to mention kind of obliviously sexist, not to understand the ramifications of winding back the clock) writing. You think that it's not necessarily out of character for Peter to be a dickhead who treats women badly but that the writers aren't necessarily up to the task of portraying that in a mutually sympathetic way without completely mangling Peter's character or letting him get off too easy for being a dickhead, and thus coming off kind of sexist.