In a loving relationship a couple must have trust and respect.
A relationship also must have some sex, but it should not be all about the sex.
One must love their lover for who they are without prejudice or judgement.
One should not judge a person and not love someone because of a certain clique they are in.
One should devote oneself to the other and always be there for the other person when they need them the most.
One should always be very faithful and not cheat.
In personal experience in my relationships the person whom I was dating was always there for me, when I needed them the most.
When I was feeling depressed and sad they were there for me to cheer me up and make me happier.
And I know that I will always do the same for the person that I love