I've been living with an older SEI for about a year now. We get along pretty much the way business relations get along, we spend our "in-between" time together quite pleasantly; we used to work at the same place and we would pleasantly bitch about everyone long into the night. We have similar practical interests, like trying to do as little work as possible, eating only very tasty food, making our surroundings pleasant to lounge about in. Mentally, we don't connect at all - I'm way too abstract and eccentric, she's too practical and shallow (IMO). However, maybe as a result of her being older and more experienced, I've learned a lot of useful things from her, like using resources around you to lessen your workload (she's really good at getting other people to do her work, in a sense), and I've exposed her to a lot of music and movies that she otherwise would not have heard of. In short, we understand and have respect for each other.
Enter ILE bf.
(Short aside: I know from the beginning that the 2 are duals, no one else knows. I've been in a situation before with an ILE f [illusionary relations with me, just like me and my bf] and an SLE m [business partner to the ILE, just like me and my roomie]. We were all good friends, and I was briefly involved with the SLE. But we had a falling out, and after the ILE told me that she couldn't stand being in the same room as me and the SLE, because we made it so awkward for everyone else with our "secret glances" and "double meanings" and generally intense interaction. I, however, wasn't aware that I was doing that at all, but I admit that we probably sort of "came to life" in each others' presence, which might have been awkward for everyone else, especially given our history. I thought it was wrong of her to kind of malign our relationship this way though, because awkward though it might have been, it was after all, a dual encounter where both parties were affected - it was almost out of our hands. Keeping all this in mind, I decide to completely withhold judgement from the case of my roomie and bf.)
And it happened just way you would imagine - they get along right away; easy conversation; big laughs at each others' jokes; intensified conversation when I leave the room, awkward when I come back; find excuses to ask me about each other; use me as an excuse to text each other...
Now, I don't think at all that there is anything romantic going on between them. SEI is engaged to her long-term bf, and ILE is very much into me. But everything I wrote above DOES happen, and c'mon - how often do you come across someone you get along with so well? They both feel it, I'm sure. When they're doing their thing, talking, I just kind of move into the periphery and let them have their moment, because I know how good that feels. And then SEI and I, with our handy Fe-creative, manouvre as gracefully as we can through any awkwardness.
But the awkwardness can be killer, at times. And to witness dual interaction like this, and not have your own dual, can feel very lonely - like, these 2 people understand each other, but no one understands me not to be melancholy or anything.