More bisexual fun with Robert and Lisa, this time

It wasn't my first meeting with them after moving back that was this memorable, but several meetings in. I remember we hung out for a while just chatting about life in general and Robert and I had some other common interests we talked about for a while. Lisa had lost a lot of weight, so she was quite proud of her new body and was walking around naked and Robert and I were just chilling in our underwear looking at stuff on the computer. Lisa walked by and said we were boring her, and she'd be much more interested in watching one of us sucking cock. I smiled and volunteered immediately.Dropping to my knees in front of the computer desk with Robert in the office chair I pulled his cock out and gave it a few gentle licks to see if he was indeed interested in playing some tonight, and sure enough he didn't take long to respond at all. He loved watching me very closely as I licked and sucked his cock. I've mentioned how large it was, the girth of it was very difficult to get in my mouth, but I did pretty well with it. I started sucking the full length of it in my mouth as best as I could and making eye contact with him until he mentioned he was getting close to cumming and wasn't really ready for that yet.So Lisa said, "lets go to the bedroom and play then!" So we did. Robert laid down on the bed and Lisa picked up where I left off sucking him, gently this time to keep him from cumming, and I climbed in bed beside her and made my way between her legs to start licking her incredibly wet by now pussy. She was in love with the way I ate her pussy, she said no one had ever eaten her out like I did, and even after trying to teach Robert the moves, nothing could compare for her, so I took my time as always and made her cum two or three times with Robert's cock in her mouth.After this, Lisa sat up and said she wanted to try something with me. She asked if I had ever had my ass played with? I said not really, had never really thought much of it, even though I knew it was a staple of bi-play. So far everything had been oral only. Lisa asked me to lay down on the bed and she proceeded to suck my cock in a very relaxed gentle method without trying to push me too far to the edge of cumming...Robert was then fumbling with a shoebox I noticed and he came back over with some lube and a small little vibrator...He handed the vibe to Lisa and she didn't even stop what she was doing with her mouth, but proceeded to gently just rub the vibrator around the base of my balls. Lisa held her hand out for Robert to put a little lube on it, and he did, and she rubbed the lube on the vibe and went back to stimulating the base of my balls and taint area moving slowly down to tease my asshole. I was still a little tense, but she was doing a great job of relaxing me by gently sucking on my cock and just gently rubbing the vibe around my asshole. Then she turned it on a very low setting, took my cock deep into her mouth and started to push with gentle pressure against my ass. At this point, Robert sensed where in the process she was, and came over by my head and placed his cock right there in my face for me to do whatever I was able to focus on...I managed to kiss it and lick it and suck the head a little between gasps of surprise as she pushed the vibe in me more and more.Lisa wasn't doing any thrusting or moving, just trying to gain some ground with the vibe deeper in me, and she got it in about 5 inches which is about all there was of it, and she just left it sitting there while she gently but thoroughly deep throated my cock. This went on for a little while as I continued to lightly suck Robert's cock. She could tell I was getting used to the sensation, so she started working the vibrator and she was moving it around gently trying to gauge my reactions to different angles. Robert decided to go help her out. He went down and took over oral duty sucking on my cock with much more energy than Lisa was, while she started working the vibe pretty vigorously until she found my prostate...I gasped...I think I said "Oh my god!" and it was then that Robert started sucking my cock deep in his mouth deep throating me while Lisa worked that didn't take me long at all to cum right down Roberts throat...he had much more tolerance for deep throating and cum than I did.I was floored, I'd never had a prostate orgasm before, and they both were laughing at how hard I came...Robert kissed Lisa so she could taste my cum too, and I watched them for a minute and decided to help finish Robert off. I sucked him while he was kissing her and he said he was close but he wanted some pussy...So he climbed up and started fucking Lisa missionary style while I alternated sucking her tits and kissing her. Robert pulled out when he was close, and I quickly went down to taste Lisa's pussy on his cock and take him over the edge. I sucked him and enjoyed that taste quite a bit, there's something different about a pussy taste from deep inside off of a cock than when you're just licking a pussy. It's distinct and much tastier. I was just making note of that difference when Robert started spurting his cum in my mouth without warning because he was already so close to coming. He was a b**st and his cum filled my mouth quickly. I still wasn't into swallowing, and they knew it so Lisa had already made her way over to help me out...she kissed me and shared the cum in my mouth during our kiss and Robert had come down too to join in kissing lisa back and forth between the two of us, all three of us now having faces covered in cum and saliva from the messy sucking and kissing that had just happened.So that was my first time with anal stimulation. I still to this day haven't had a cock in my ass and would love to experiment with the right one, not too big, but I definitely enjoyed the stimulation.