Ah I see. Glad to hear that he is not alone. I have two female cats and they seem to enjoy staying near me. They are anti others most of the time haha. I'm a quiet person and doesn't annoy the cats like others and maybe that's why.
It's too sad to hear that he got Parvo but he recovered so he a strong boy but it probably weakned his immunity and made him more susceptible to infections. I hope the medication works and he recovers fully.