Every once in a blue moon there arises an occasion when your roommate may invite their partner for a weekend together at home. While there may be some discomfiture over this ordeal, it is not an insurmountable task. With a little patience and adjustment it is a doable task without you having to pack your bags and run away to another friend’s place for the weekend.
The foremost thing that should be established in your roommate agreement when one of you decides to bring home a partner is limits as to how much are you willing to compromise and adjust. If giving up the play station or tv so that the couple can enjoy some comfy time on the sofa in the living room is ok with you, say it. If not, be clear about you not being comfortable. Most importantly make a ground rule of informing each other beforehand when a partner comes over. You don’t want to walk into your roommate’s room in towel asking for shaving foam when he is with his girlfriend.
Giving space to the couple will be one of the requested agenda by your roommate. While you may comply by it, it doesn’t necessarily mean you make yourself invisible or stop going to the kitchen or living area. When invited for a dinner or lunch, feel free to join but do know that it is best to leave the couple alone after 11 PM.
When you or your roommate come home with a partner it is best to introduce him or her to everyone instead of sneaking them in. You are an adult, not a school boy or girl. As a roommate make sure you have a civil talk with them. They are your roommate’s partner not an alien. Try mingling once in awhile.
While there is no strict protocol on how you should be around your roommate’s partner, it all boils down to how friendly you are with his or her partner. If it is someone above your tolerance capacity limiting yourself socially would probably be the best policy.