Keep an eye out for these things, because they could mean trouble.
The things that used to excite you about your partner now annoy you.
You feel constantly nagged.
You constantly fantasize about someone else especially if that someone is not in a relationship or perhaps they may be depending on your leanings.
You take every opportunity to be elsewhere when you should be having your quality time with your partner.
You make constant “reasonable” excuses for not having sex, when you were like an “addict” previously.
You are in denial that anything is wrong, though you know the relationship has changed.
Everything about your partner becomes more and more offensive to you. You compare them to others more and more frequently, constantly wishing they were someone else.
You start spending less and less of your social time with them, whereas before you could not live without them.
You start flirting with other people and playing with fire.
You are having an affair with someone else, perhaps feeling guilty about it but doing it all the same or maybe even blaming your partner for the affair though you are the one having a “fling”.
