Ticklish situations may emerge when you're in an exclusive relationship, and your closest friends are extremely comfortable doing just about anything that they desire with you. Imagine now that there is only one friend, and that this friend is of the opposite sex. Potentially turbulent waters? How comfortable are you with your significant other having a best-friend of the opposite sex? Let’s navigate together.
The values of respect and trust are to be greatly protected. It is important that you both offer and preserve respect and trust while allowing each other individual space to have friends who are not necessarily mutual. If there are special friends (or a special friend), these friends should be introduced to your partner. After the grand introduction, there should be an understanding of the relationships that leave no room for doubt or misunderstanding.
If your friends are "Mark" and "Michelle", Mark and Michelle must understand both relationships, and respect your relationship with your partner. If Mark and Michelle choose not to respect your relationship with your partner, it means that they do not respect you, and they should not be allowed to dwell in your space. I am not advocating an abrupt or violent separation, but an understanding by both that things toxic or debilitating to the relationship (however harmless otherwise) must be kept at a safe distance.
Great relationships don't just happen. If you do not protect your love, it might get stolen.
As your relationship progresses, you both, together, should set boundaries for friends. Your friend can steal your heart, and your partner's heart can be stolen too. You both should decide to be on the lookout for thieves, and setting borders can let you know if your friend or your partner's friend can be trusted. If the borders set are being crossed, plant a stop on the track. No one is allowed on exclusive territory! If you realize that your close friend is interested in more than just a friendship, and will not respect the stop sign, please share the information with your spouse and cut that person off, because obviously, that friend does not respect you or your relationship.
As social beings, it is normal and healthy to have good friends and even best friends of the opposite sex. However, there must be wisdom applied. Preserve respect and trust while protecting each other, because these are what will make it last.