I briefly considered not going back out to the hot-tub. I was feeling a bit tired myself and thought this might be the perfect opportunity to sleep in my own bed and actually get a full nights rest for the first time in nearly a week.
But it was Jen's birthday, and she had directly asked me to come back out after putting Collette to bed. In the end, I couldn't just disappear after she'd asked me to return, not on her birthday. So I went down the stairs and headed for the glass door to the backyard.
The sun had gone down a little while ago, making the backyard rather dim. Jennifer and Tammy were still in the hot-tub together, but no longer just sitting side-by-side. Jennifer was now sitting on Tammy's lap, facing her, Tammy's arms running up and down Jen's back, Jens hands running through Tammy's hair, their lips locked in a passionate kiss. I waited for a moment and watched as I didn't want to disturb them, and, well, frankly, just so I could watch. To this day, there is nothing quite so erotic to me as watching two beautiful young women eagerly and passionately kissing. My right hand absently drifted down to my fully erect cock and lazily squeezed.
As their kiss continued, Tammy's hands settled at Jen's bikini strap and worked the clasp loose. Her fingers drifted slowly around and under Jen's arm as they continued to kiss, their tongues briefly visible from time to time as their mouths worked together. As her fingers reached the front of Jen's breast and moved the loose bikini aside, Tammy slowly broke the kiss and moved her head down until her lips met Jen's small breast, puckering to kiss her erect nipple twice before sucking it between her full lips. Jen pulled Tammy's head into her chest with one hand while the other removed the loose bikini top from around her head. Looking to the side where she was tossing it, Jen noticed me staring at them through the glass door.
I was a bit embarrassed at having bet caught, not just staring at Jen and Tammy as they were intimately engaged, but also realizing that my hand was still squeezing my own crotch through my swimsuit in full view through the window. Jennifer didn't seem to mind as she smiled at me, tossed her swimsuit top aside onto the patio, and then gestured her finger at me in a come-hither fashion while Tammy's face was still preoccupied with her breast.
Considering the invitation, and realizing that this could be much more interesting up close, I ignored my inhibitions and walked through the door toward the hot-tub. Tammy must have heard the door open as she slowly lookup up from Jen's swollen nipple and smiled at me.
Jen pointed to the patio table as I walked toward them, "Mark, grab those shot glasses and the tequila on your way over." Tammy looked up when she heard Jen talking and smiled at me.
"Ok", I said, grabbing the tray. There were six shot glasses and a large bottle of expensive tequila sitting on it. One of them must have put it together while I'd been in the house with Colette, because it hadn't been there before.
Jen slid off of Tammy as I approached and put the tray on the small table next to the hot-tub.
"Now pour six shots," Jen said, "we're going to play a little game." She gave me her winning grin as I opened the bottle and filled all six glasses.
"Each of us will take a turn," Jen said as I climbed into the hot tub, "You have to tell two true things about you and one lie, then the other two guess which one is the lie. Whoever guesses wrong has to take a shot. If someone guesses correctly, the person who lied has to drink their shot." Tammy and I both laughed and agreed to play Jen's birthday drinking game.
"Ok, I'll go first!" Jen said, "Tammy is the only girl I've ever made out with. Collette is the only one I've ever smoked marijuana with. And Mark is the only guy (other than my father) who's ever seen me completely naked."
"That's easy," I said, confident of my answer, "the third one is the lie." Jen smiled.
"What about you, Tammy?" Jen asked.
"Well, I'm pretty sure the first one is true," Tammy replied, "but I don't know about the other two. I'm going to go with Mark, I think the third is the lie. I know you've slept with at least one other guy." That answered one question for me, at least. I was now certain that Tammy knew I had sex with Jen.
Jen just started laughing. "You are both wrong," She said, "take your shots!"
"You're kidding!" I said, surprised, "How is it that I'm the only guy who's ever seen you naked? Which one is the lie?"
"I had sex with one other guy," Jen said, "but I still had a T-shirt on. And I'm not telling you which one is the lie, you have to figure that out on your own!"
Tammy and I both took our shots and drank them down quickly.
"Ok, Tammy, your turn." Jen said.
"Alright. Jen's the only girl I ever had sex with. I spent a night in jail once. And I've never had sex with a guy."
"You first, Mark," Jen said, "I know too much, I don't want to color your answer!"
"Fine." I said, "I'm going to go with the second one as the lie."
"Really?" Jen said, "you really think she's that chaste?"
"I don't want to make any assumptions," I said, "Tammy strikes me as a very nice girl, I can't believe she's ever been to jail."
"Well," Jen said, "I'm going to call BS on the last one. I can't believe you've never had sex with another girl, much less with a guy!"
"Funny girl," Tammy said, giving Jen a kiss on the cheek, "drink up!"
Tammy took two shots off the table, handed one to Jen, and downed the other herself.
"He was right?" Jen asked, incredulous.