What is a kind but direct way to tell a clueless couple I’m friends with that I want to close the door on the prospect of a threesome?

I(32F) have a coworker friend(29M) who started dating a woman(29F) around the same time we met about 4 years ago. I’ve met her once or twice over the years in party settings and we got along.

They’re bisexual and have discussed opening up their relationship, including threesomes. I’d been getting flirtier vibes from them and was eventually told that they wanted a threesome with me.

I told them the truth – that I’d felt that energy from them, that I had thought about it before, and that I’m open to the idea of it happening some day but am currently leaning heavily into a “go with the flow” state of being. I’m starting to regret not saying a direct no.

The truth is that for a number of reasons, I’m just not *that* into the idea. What I told them was truthful but I meant it in the *most* casual of ways. I normally see these two as a couple like 1-2 a year so I didn’t anticipate there being much opportunity but figured if the stars align some night then sure!

Suddenly my coworker, acting as messenger for them both, started requesting hangouts much more frequently. I agreed at first but started to not enjoy the frequency of our hangouts or the way those times made me feel.

I tried giving subtle clues but they didn’t understand. I more directly texted my coworker saying that things felt too intentional for me and reiterated how that’s not aligned with how I’m trying to live right now. Things seemed to tone down a little but I still feel like they’re putting in work to get me in bed and at this point I am turned off by them and not at all interested.

I’d rather not have to tell them the reasons *why* I’m turned off (not just what’s mentioned here) or how my maybe become a no but I do want to make it abundantly clear so I don’t have to think about any of this if/when I do decide to spend time with them.

How can I get myself out of the situation with as few hurt feelings and bruised egos as possible? (Neither of them have a lot of dating or sexual experience so I want to be sensitive to that if possible.)