The only correct way to say that is "We are in a relationship." Relationships is plural and refers to 2 or more relationships. For example, the one you have with your mom, your partner, your friend and so forth. Those, all combined, are relationships. I hope this helps Anthony. If not, please feel free to ask.

Relationship is the right word to use. It can describe the connection between two people, a person and a group, or between groups. Some examples My girlfriend and I are in a relationship. My girlfriend and I are in a working relationship. I have a good working relationship with the company. The countries have a good relationship.

It would be better to say "relationship" in both cases. The interaction between your girlfriend and yourself is treated as one thing, one "relationship". The same line of thinking goes for the "working relationship" example. If you wanted to use "relationships", there would need to be several people involved. An example: I have good relationships with John, Mary, and Bill. Hope this helps!

You would always say it in singular, relationship (in both cases), because it is ONE relationship involving the two of you.