Guys stop being harsh on him and hate him 
he was clearly confused about his sexuality and his feelings 
The first time he rejected him he was indeed mean but he didn't meant it
The second time he clearly liked him but he was afraid and confused about how he felt 
And he's trying to get him back because he realized his mistake ad he's trying to fix it 
so no he's not a red flag, he's a good guy 
but I totally understand how the other guy is feeling