Some men truly don’t recognize that their friendships with women cross over into inappropriateness. Most of the times, it becomes terse, dry and arid. You have to moist your relation with the steam of love and care.
Try saying something like, “I love the relationship that we have and I trust YOU, but I am uncomfortable with how close you are to ….”. usually our response becomes much more accusatory causing our partner to become defensive. Your partner will not fine you, first palatable then, tolerable.
Don’t make your mate feel sorry; protect his/her honor as you do it with yours.
Your partner may truly see nothing wrong with its special relationship, especially if it truly has not developed intense romantic feelings toward the outsider. Explain your partner calmly that his/her motives behind the friendship are not in question, but that his/her behavior (spending one-on-one time with the outsider, confiding in one another, not integrating you into the friendship) is inappropriate for someone in a committed relationship and it needs to be changed.
Let your partner know, in no uncertain terms, what you are and are not comfortable with. For example, “I’d prefer that you and the outsider not spend time alone, but I’d be happy to go out as a group.”
Setting boundaries is healthy. Following through with maintaining them is even more important. If the partner doesn’t respect them, you may have bigger problems in future than this outsider.
Show your partner that he/she doesn’t need to look to another one to get his/her emotional needs met. You can do this by demonstrating more of an interest in his/her life. For example, instead of just saying, “Hi honey, how was your day,” try getting more specific, “So…tell me about the …(name a special happening of his/her day)!”
Actions definitely do speak louder than words. Just as it’s important that you make sure your own physical/mental/emotional needs are getting met, your partner needs to be sure about his/her ones. If you aren’t interested in meeting them, it only makes sense that the partner would get them met somewhere else.
I’m simply saying that relationships are give and take…on both sides.
If your partner violates the boundaries that you set (or refuses to agree to them in the first place), break off the relationship. He can’t have his cake and eat it too, and you deserve to be with the one who will make you the #1 companion in his life… REALLY.