Relationships do not always end happily.
But many of them end because people are often unable to see the problem and deal with it while they can. The signs are the key to a successful relationship. But of course, the signs may lie. That is why communication should also be your source of information.
And this applies to all aspects of a relationship. Even sex. Which can make things pretty complicated, right? Well, if you think that there might be something wrong with sex in your relationship then you should definitely watch out for signs. 
For example, if you think that your partner might be interested in a change, then you should definitely watch out for these signs:
- Avoiding sex. If your partner loses interest in sex, then it might be a problem for your relationship. Although there may be various reasons for that, you should be careful.
- The interest in trying new things. Is your partner always asking you to try new things in bed? Well, that is a good thing! It means that your partner is interested in improving your sex life together! So, go ahead and talk to them.
- They are learning new things. Sometimes when your partner comes with something new, it does not have to be the sign that they are cheating. Maybe they are just educating themselves.
- They suggest getting help. This does not have to be a bad idea! Asking a professional for advice may be actually very helpful.
So, now you know what you should watch out for! So be patient and communicate with your partner about sex openly! There is nothing worse then not discussing this kind of thing. Sex is important for your relationship and therefore it cannot be neglected.
But that is all up to both of you. You need to deal with this as a couple. Therefore remember to always be clear and open with your partner.