Mat 26:48 Now he that betrayed him gave them a sign, saying, Whomsoever I shall kiss, that same is he: hold him fast.
Mat 26:49 And forthwith he came to Jesus, and said, Hail, master; and kissed him.
Mat 26:50 And Jesus said unto him, Friend, wherefore art thou come? Then came they, and laid hands on Jesus, and took him.
Mat 5:44 But I say unto you, Love your enemies, bless them that curse you, do good to them that hate you, and pray for them which despitefully use you, and persecute you.
Jesus loved all the disciples, even Judas, as well as all people.
But when it says the disciple whom Jesus loved it means they were closer to each other, as compared to the other disciples, but this was because of John's attitude towards Jesus.
Jesus loved all His disciples but it was John's attitude of wanting to be closer to Jesus why it is the disciple whom Jesus loved for it caused a close relationship between them.
Jesus would be fair over all people that followed Him to be close to them all equally, but some people wanted to be closer to Jesus than others, although they all wanted a relationship with Him.