A few months and several more pleasurable encounters after that first amazing threesome, Sarah fell into some living trouble when her current housemates all found different places to move out, leaving her unable to afford the rent on her own. She had noticed, in all the extra time she'd been spending at our place lately, that our apartment had a spare bedroom we'd really only been using for storage.
It was a proposition we had to think carefully about. Moving in together as a couple had meant to be the moment both Katie and I stopped dealing with housemates and sharing accommodation. We were grown adults who didn't want to worry about privacy the way we used to.
But then, if it was just Sarah, we still wouldn't have to.
The rules were established quickly. We would keep sleeping together as a trio, but with the understanding that Katie and I were going to remain the couple in the middle of that. Sarah got her own room in case she ended up bringing someone home and the freedom to date and fuck whoever she wanted, provided she did so safely.
As for everything else, we just did whatever we wanted. Whatever felt right in the moment. The apartment didn't become a nonstop nudist orgy overnight or anything, but we got pretty damn casual about our bodies and libidos pretty quickly. Naked walks from bedrooms to the bathroom were done sans towels, and coming to breakfast half dressed in mostly underwear wasn't an issue. Doors were left open for changing, washing, masturbating and even fucking, with audiences and assistance welcome. When one of us felt horny, he or she would strip down and openly flaunt their body through the apartment naked, or in lingerie, harnesses and other gear that would enhance our nakedness rather than hide it, waiting to be taking up on the implicit offer. Open displays of arousal at what we saw were encouraged and often rewarded, usually right where they happened. I got blown, got jerked off, ate pussy and fucked in the living room, the kitchen, the bathroom and both bedrooms, usually with the other girl watching from the doorway. I would watch them the same way, joining in if I was invited and touching myself to the show if I wasn't.
The things I saw in the first week alone would keep you turned on for a year. I wish I could write up every individual encounter for you, but these things take a long time to type when I always end up having to do it one-handed.
By now, we were all sleeping nude, or at least bottomless, and with an open-door policy. Generally, we started out in our own rooms. On some nights, Sarah appeared in our doorway, already aroused and lubed up for a quick threesome. On other nights, Katie decided she wanted a feminine touch for her pre-sleep fuck and slipped out of the covers to join Sarah in her room. She would give me a big kiss to let me know I was still wanted, and promised to make it up to me the next night. I would either creep out to spy on them or just jerk myself off to the unrestrained cries of pleasure resonating through the walls. It could be as fun imagining what they might be doing to each other as it was knowing for sure. Other nights, I decided I wanted to enjoy the feel of Sarah's thicker, plusher tits and ass and would leave Katie with a kiss and a promise the same way. Some nights we both went to her together after working ourselves up discussing how we wanted to fuck her. On one memorable occasion, we all met in the living room, planning the same thing, and had one of our hottest threesomes yet on the couch.
Sarah also liked to surprise us at night. She would sneak in the open door, quiet as she could, and worm her way under the covers from the bottom, climbing the legs of either Katie or I until she found cock or pussy and giving oral until we woke up.
There was something that really tickled me about the nights she would eat Katie out by my side. The noises they made woke me and my cock up too, and I would jerk myself off to Katie's pleasure. I would turn sideways and use the softness of her midriff to stimulate the tip while I worked the shaft. When I got close to finishing, I would get up on my knees and spray cum over Katie's tits and mouth while she rolled under waves of pleasure from what Sarah was doing to her cunt. The view and the feeling had no equal.