Sometimes the signs are there, but you don't always see them. Sure, in long term marriages/partnerships things can become a little hum-drum but how do you know if he/she's really losing interest in the relationship? Here are some signs
1. He/she stops kissing you hello or goodbye when they always used to
2. He/she doesn't want to participate in any family activities like they did in the past.
3. The typical working very late hours and not having enough time to spend with you or family.
4. They would rather be out with their friends more than usual.
5. They quit listening to what you have to say and don't make conversation like usual.
6. Other people become more important to them, more than you or the family.
7. They become more slobbier than usual and dress up only when going out without you.
8. They become more disrespectful.
9. They say things to pick more fights.
10. They start doing more things individually and less of togetherness.