Everyone involved is over 18.
I had some evening free time, so I decided to go visit one of my local porn theaters. When I got there, the guy who works the day shift said, "Glad you didn't come earlier, as it was really quiet." That told me there were already people in the theater, so I went in, grabbed a seat, and strapped on my knee pads.
I went to the middle room (they have 3), which usually shows bi porn. There was a guy stroking his hard 6" cock. Decently thick too. I glanced over into the male-on-male porn room, and there was just one guy who was chilling watching the video. So I looked over at the guy stroking himself and asked if he wanted some help. He said sure and released his cock. I dropped to my knees and began licking his shaft up and down, then I slowly slid him all the way into my mouth. I heard him groan out, saying "oh yeaaaaaahhhh" as the head of his cock rubbed against the roof of my mouth and my tongue caressed the underside of his shaft.
I began to slowly slide his hard meat out until his big plump head was on my lips, then slowly slide back down again. I kept my mouth tight, feeling my lips glide up and over the raised crown of his cock head.
After several minutes of slow, powerful sucking, I licked my way down to his balls. I used my tongue to slather them, then took one of his balls into my mouth. While I suckled it, I stroked his cock with my hand.
I let the first ball slide out and then sucked in the other. After sucking it a bit, I pulled them both in, so that each of his full orbs were enveloped by my hot wet mouth. This elicited a throaty "oh fuuuuck" from him.
I released his balls, then licked my way back up to his cock. 
As I was about to take him in, the guy that was in the male-male porn room walked in. He stood next to me, watching, and pulled his cock out and began stroking.
I love having an audience, so I tilted my head to look up at him while I slid my tongue around on the big cock head in front of me, then slowly took him all the way in again.
The guy I was blowing put his hands on my head as I glided up and down, slowly increasing my speed. I could feel his balls twitching, his legs bouncing, and his breath quickening. 
"I'm going to cum!" he moaned. He put his hand on his cock and began jerking off in front of my face.
I opened my mouth so that the guy watching could have a good view of what was building up.
Hot cream fired out of his thick head and shot into my mouth. He fired a couple more streams, which I quickly swallowed, then proceeded to deep throat him so that I could lick and suck up the remaining juice.
Once he was empty, I sat back and swallowed again. I looked over at the guy that was watching us. He grabbed my head and immediately shoved his cock in my mouth. He was about 5.5" and began fucking my mouth hard.
Within minutes, he began cumming and emptied his balls in my mouth. I pulled off him and swallowed. He quickly put himself away and walked out. I took a seat next to the first guy I was blowing and drank some water.
"Wow that was really hot," he exclaimed.
"Yeah. That was crazy. I need to rehydrate after that," I said, drinking more water.
I got up to get some blood back in my legs and walked into the main room. There was a guy I had been with before. He had an average-thickness cock, about 6.5" in length. He was stroking himself, watching the straight porn on video.
I took a seat next to him.
"I remember you," he said. "You were really good at tickling my balls. I've been edging all day."
I knew he liked to have his balls "tickled" while he stroked himself.
"You can tickle them if you want," he said invitingly. 
I reached over and began running my fingers and nails gently across his ball sack. ever so lightly stroking them.
"If I tell you to stop, don't", he informed me.
So I continued to lightly touch, stroke, and tickle his balls.
"You'd better stop...you're getting me close," he moaned.
"I'm not going to. I want to see all that hot cum of yours."
He whimpered as I continued to lightly work his full balls over.
We did this for about 20 minutes when someone new walked in.
<editing out hooking up with an older lady>
"Holy shit that was fucking hot," he exclaimed. "I'm *really* close to cumming now!"
I reached over and resumed stroking his balls while he jack-hammered his cock.
Soon, he started erupting, pumping hot cum up and all over his and my hand. I licked off the cum that he spurted onto me.
"Wow. Thanks. That was fantastic.", he gasped, a huge smile across his face.
He cleaned up and headed out, so I relaxed and had some water to rehydrate.
After a while, an older guy came in and sat a few chairs away from me. Shortly after him, a guy who looked in his late 30s came in. He stood near me. 
A few minutes went by, and I noticed the guy in his 30s had a tent going on in his pants. I opened my mouth, slowly licking my lips, as I wantonly stared at his groin. He took the hint and came to sit by me, then pulled his cock out.
He was about 6", and on the thinner side. I asked him if I could suck him. He smiled and said, "I'd love that."
I got down between his legs and immediately began licking all over his cock. He was ROCK hard, and I took him into my mouth. I slid all the way down and licked his balls.
As I did, he puts his hands on the back of my head and groaned.
I stayed there for a few seconds, then pulled back up and started quickly driving his iron cock in and out of my mouth. My hands cradled his balls and stroked his shaft while I sucked him.
I did this for several minutes and could tell he wasn't going to last long.
"Oh god you suck good," he panted, looking down at me. "You're going to make me cum soon."
I paused for a moment, looking up at him. "Yum. I hope so," then resumed power-sucking him.
He was staring down at me, devouring his tool.
"You want it? You want my hot cum? Get ready!"
I kept suctioning him, my pace never slowing. His dick started lurching as hot streamers of cum began pulsing out into my mouth.
After he finished, I pulled back. I opened my mouth to show him his work, then swallowed and licked my lips.
"God you're good," he said, exhaustedly.
I smiled. "Thanks." 
He stood up and got dressed. I noticed the older guy was groping his groin. I got up and sat back down. The older guy and I both just chilled there for a bit, then he stood up, unzipped, and pulled his cock out. It was about 5" but really thick. I motioned him over to me.
He walked over, his groin level with my face, and I opened my mouth wide to take it in. He put his hands on top of my head, then began thrusting his hips, sliding his thick meaty cock in and out of my mouth.
I gripped the base of his cock, squeezing it a bit, and added extra pressure from my lips as I sucked his girthy unit. 
His thrusting sped up, and I could hear him breathing hard. Then he was cumming, a thick molten deposit ejaculated out of his cock and onto my tongue. 
I cleaned him and suckled out the remaining load. He patted my shoulder, put himself away, then rezipped and left. I relaxed again, drinking more water.
After some more time went by, another guy (who looked to be in his late 40s) walked in and made his way to the back male-on-male room. I gave him time to get situated, then got up to go check things out.
He had his cock out, slowly pulling on it. I sat next to him and asked if he'd like some oral. He nodded, so I got between his legs.
He was about 6.5" and pretty thick, so I started off moistening up his pole by licking it up and down, paying special attention to the head. Then I took him all the way in.
"Ooo...that's nice. Yeah. Suck that dick," I heard him mutter.
I slowly worked his cock in and out of my mouth. As I was doing this, a younger guy walked in and sat near us. I made sure to give him a show and let him see me tonguing, licking, and slurping on the fat cock in front of me. Then made sure he could see me take it all the way in.
He quickly had his cock out and started jerking off. It was about 7" and thinner.
After a bit of sucking, I pulled the thicker cock out of my mouth. The younger guy, who was watching us with a deep hunger, leaned forward and sucked him a bit. While he did, I reached over and began fondling his cock.
He only sucked for a minute or two, then stood up. He grabbed my head and started fucking my mouth. The guy with the thicker cock was watching this all, and stroking himself.
I heard him start quickly grunting, his thrusts becoming more erratic. He pulled himself out of my mouth and started fisting his cock. I opened my mouth and let out my tongue. He was gasping and near orgasm.
"Cum in my mouth," I pleaded. He started cumming, hot cream pumping out onto my tongue. I took him deep and swallowed his load.
Once he had finished, he pulled his cock out, put himself away, then left. So I resumed sucking the guy with the thicker cock. 
He liked it slow, with lots of pressure. So I would keep my lips tight around his pole while I slowly slid him in and out.
After about 10 minutes of this, another guy walked in and sat next to us. He looked to be in his 40s, and after watching us for a bit he pulled his hard cock out. 
He was about 7.5" and thinner. 
I looked up at the guy I was blowing, and he motioned me to take care of the new guy.
So I went over and got between his legs. I didn't say anything, just immediately started licking and sucking him. The guy with the thicker cock leaned over and played with the new guy's hard nipples while I sucked hard and fast.
When I would take him all the way in, he'd hold me close feeling his cock head rub against the roof of my mouth and my tongue caressing his shaft. Then he'd release me and I'd resume slurping and sucking him.
It only took about 10 minutes for him to tense up and shoot a thick heavy load of cream in my mouth and down my throat. I swallowed him and then pulled off. He zipped up and then walked out.
The thicker cocked said he needed a break, which was perfect because I did as well. I walked around outside a bit, getting blood back in my legs, and drinking some water to rehydrate.
When I came back, there was a 3-some going on in the main room. A guy in his early 30s, getting blown by another guy. The thick-cocked guy I had just been with was with them, playing with the ass of the guy getting blown.
I watched this all for a bit, then the guy sucking suddenly disengaged and left. The guy getting blown hadn't cum, that I was aware of. He then got on his knees on the mattress, and the thick-cocked guy got behind him and started eating his ass. I looked down and the guy getting eaten had a thick 8" cock  that was needing attention. So I crawled underneath him and began sucking his dick.
We kept at this for a while, and eventually changed positions a couple of times. Eventually, the 8" cock guy ended up on his back, so that the thick-cocked guy could finger-fuck him and I could lean over and suck the big 8"er.
We did this for about 15 minutes, and then the 8" cock guy took hold of his dick and began jacking it. 
"Oh fuck I'm so close. I'm going to cum!"
I put my face over his dick, just as it erupted. He shot thick ropes of hot cum all over my mouth, chin and lips. His load spewed all over his dick, which I licked up and used his beefy cock to push the cum on my face into my mouth. I then throated him a couple of times, suckling out any remaining jizz.
"God damn that was hot," he gasped.
It was time for me to leave, so I told him thanks for the big meal, then looked over at the thick-cocked guy.
"Great teamwork," I laughed. He smiled, and we all said goodbye.