When the subject performs a particular action, it means that the sentence is active rather than passive. If the object was the focus of the sentence, then it would be a passive sentence. For example: I love reading books - active sentence Books are written by writers - passive sentence
These sentences can be in future, past, or present tense - which means that tense is not important.
I would think that "insensitive" meant that his other girlfriends thought he didn't care, or he was a total idiot or soemthing. Just something like that. I hope this helped a little bit love!
