"You look like you're drowning in that thing," I said to her.

She pulled her mask off. "Yeah, it's hot in here too."

She took a drink, and we were both quiet for a while. Then Erin smiled.

"You want to have some fun? Get in here with me."

I was a little surprised. She wasn't usually this "cozy" with me, maybe the alcohol was affecting her. But I was never one to turn down intimate contact with a hot girl.

"Are you serious?" I asked.

She shrugged. "Yeah, it'll be fun. There's definitely enough room in here. We'll see how long it takes for Mom and Dad to find you."

She tried to reach her back to unzip the costume, but she couldn't stretch that far.

I took another look at her panties, and the shapely ass inside of them, and immediately took the suit off, glancing around to make sure no one could see us. I threw the alien suit into the corner and stood there in my boxers. I stepped inside the suit and suddenly felt the warmth from Erin's body. I was pressed against her backside, and my crotch was lined up right at her ass. It was a little embarrassing, but I quickly reached behind me and zipped the suit up.

The mask was a little bit of a tight fit, and my face ended up in her hair, but I was too distracted by the feel of her body pressed against mine to really care. She adjusted to the feel of both of us inside the suit.

"This is so funny," she said. "Can we even walk in this thing?"

"Try it," I said. "Just start walking and I'll follow your lead."

"I have to go to the bathroom," Erin said.

We struggled a bit going up the stairs, but we made it to the bathroom. I unzipped the costume and shut the door behind us.

We both breathed in relief a bit, after being closed up inside the hot tiger suit. Before I could say anything, Erin stepped out of the suit completely and went for the toilet.

"Do you...want me to leave?" I asked.

"Are you going to stand in the hallway in that suit? It'll give us away."

She lifted the lid and pulled her panties down, right in front of me. I couldn't help but stare at her, she didn't even try to cover herself up. She sat on the toilet, her eyes wandering to my crotch. I followed her gaze, to see my erection quite obviously pressing through my boxers. The suit had sagged below my waistline. I pulled the suit up, hiding myself from view.

"You know," she said. "You look like you need to...relieve youself."

I couldn't believe what she said. "What? No, I don't...I mean, of course not. I'm not...it's not you..."

"Well of course it's me," she said. "I just didn't know if you were...hard, you know, because you needed to."

I had never been more embarrassed in my life. "I'm so sorry, I didn't mean to...you know."

She shook her head. "No, it's okay. You know what?"

Just then she reached behind her back and unhooked her bra. She took it off right in front of me, and threw it aside. Then she hooked her thumbs inside her panties and pulled them down. I watched in total shock as she kicked them off and stood before me completely naked. I had always thought she had a great body before, but to see her naked like this was so much hotter!

She paused for a second, as if to give me a full view.

"Don't say anything, just take your shorts off," she said.

We stood there quietly, in front of the bathroom sink, crushed against each other. We were both breathing heavier, and Erin was clenching her ass around my dick. I felt brave and made the first move. I thrust my dick further up her ass crack, and then slid back down. Erin gasped, obviously enjoying the sensation. I did it again, and she again responded with increased arousal.

I began sliding up and down between her ass cheeks, fucking her ass without any penetration. She braced herself against the countertop, leaning forward while I thrust into her ass. It felt great, and I was already so hot from seeing her naked that I felt my loins stir.

"Wait," I said, "or I'll cum."