My mate and I are in an open relationship that he asked me for, so he could have sex with other people. I am having sex with someone else too, but I am falling for him. I still love my mate, though. How do I tell him that I have feelings for someone else?
Received via Telegram (name withheld by request)
It is definitely easier to discuss that situation before it happens, but even if it has already happened, it may be less traumatic if you roll it out as a hypothetical.
Tell your mate something like, "I know our relationship is open because we both enjoy having sex with other people while having each other for romance and emotional support, but there's always a risk that one of us might fall for another guy; sex is an incredibly intimate experience, and sometimes emotions get involved whether we want them to or not. How do you think we'd handle that situation? Would we simply disclose the information and continue the status quo? Would we break up over it? Would we move towards being polyamorous instead, and date the new love interest either individually or as a couple? Would we cut all ties with the person we developed feelings for for the sake of our existing relationship?"
When you ask your mate about the situation as a hypothetical, you can see where he stands on the issue without immediately triggering a robust emotional outburst if he feels intensely jealous.
If your mate has a really bad reaction to the question, then you know that it might be best to steer clear of the conversation until he cools off. At that point, you may be in the position of choosing between your existing relationship under your old terms and a new relationship with the guy you are falling for, at the expense of your existing relationship. If you decide you still need to tell your mate about the current situation, you might then choose to break it to him incredibly gently.
If your mate's reaction is instead more neutral or positive, then you can follow up with "I actually think I might be developing some feelings for [new guy], and I wanted to tell you so we could work through it together."
In the latter case, allow your partner to take the lead and play off of his responses. Ask him how he'd like you to handle the situation, and ask him what he'd do in the situation you're finding yourself in. Make sure you advocate for yourself and what feels right to you, but it's probably a good idea to take a somewhat deferential stance. Acknowledge that the feelings you're experiencing are outside of what was permissible under your old relationship terms, but tell your mate you want to focus on staying positive and handling the situation as it stands while avoiding petty recriminations.
Once you and your mate have discussed the scenario, consider going through this exercise with your mate:
Each of you writes up three things: 1) what your ideal outcome for the situation would be, 2) what you could find tolerable and live with, and 3) what you simply could not accept. Once you have each written these outcomes down, share them with each other and discuss similarities and differences. Hopefully you'll find enough common ground that you can move forward constructively.
On a final note, it's really important that you remember to communicate with your new love interest! He has feelings too, and he has a right to know where he stands with you, to know what his relationship prospects are, and to advocate for his own interests. You might consider performing the exercise I just described with your new love interest also, perhaps even before doing so with your mate, and using his responses in part to inform what your acceptable outcomes are that you discuss with your mate.
Your new love interest's feelings are no less important than yours or your mate's, and that doesn't change simply because you and your mate are in an "official" relationship — always remember that the people in a relationship are more important than the relationship, and that includes any secondary or sex partners you might have.