What does this mean?

So I have a boyfriend and we’ve been together for a while but I always forget about him I know it sounds weird but i never even think about him or remember he exists unless I’m horny then he will pop in to my mind. I can go weeks without thinking to message or talk to him he’s always messaging me but I can never be bothered to reply. What does this mean? Does it mean I’m not interested in him it’s not only him its happened with it happens with every guy I speak to I just have no interest in them unless I’m horny