In a longterm relationship that is open. I've done some app-dates that never moved ahead, however my partner had another casual connection for around a year that ended recently. This was awesome, and I've discovered and embraced the concept of "compersion" for my partner in their explorations with others. The apps are good because you start on an even footing of co-understanding of what you're both there for (in theory!). However, I think I'm discovering that I'd much prefer to just be more intimate with open-minded friends, than actively seek out connections online (no judgement to anyone who views this differently though).

Me and my partner have a mutual friend who I would like to move into a more intimate connection with. We have good chemistry and they have been in non-monog relationships themselves. My partner has been supportive about me developing this as well.

The only problem is I'm really unsure about how to approach it with this person. We have an established friendship, which I value, and am a bit afraid of compromising this by attempting to develop that into something more intimate.

I'm looking for ideas or insights from other people who have been in this situation about how to approach this matter sensitively. Help?