If he has herpes, why is he dating someone with brain cancer? I need some opinions please!?

Why would he get involved with someone with brain cancer knowing he has herpes. He said he was tired of our long distance relationship and he was lonely. He says he's still in love with me and wants to marry me oneday when I get there but why is he with her? Yet he's having sex and dating this girl with brain cancer. I don't get it? Another thing is he said I don't want to date a dark skinned girl and he has always said that. This girl he's with is really dark. He has a big booty fetish could that be it because she has that. He also said he don't love her but he has feelings for her? What does having feelings mean? I just don't get what he's thinking about! I thought after he found out he had std's he would stop cheating, now he's with someone else.