For the next few days grandma Rosie and I ended each day in her bed, masturbating each other, ending with both of us having bed shaking orgasms. If we went out during the day, we acted like a normal grandson/doting grandmother, but once back inside the confines of her house we were more like horny teenagers (technically I still was one, but that's not the point), constantly groping or flashing each other before hopping into bed at night and having our nightly sessions. But I wanted more, and (as I found out later) so did she. I took the initiative.
About a week after our first time bringing each other off I decided to make my move. I heard grandma go into the bathroom to take her shower. I waited a couple of minutes before stripping off my shorts and heading to the bathroom. I peeked in the door like I had a couple weeks back, but instead of rubbing one out while peeking in on her, I pushed the door open, pulled the shower curtain back and stepped in behind her.
"Alex!" she exclaimed when I wrapped my arms around her and grabbed her huge tits and pressed my hard cock into her back, just above her firm ass.
"What?" I asked innocently while nuzzling her neck.
"What are you... oh that feels good..."
I had taken the soap from her and started lathering up her tits. She pushed back into me, squeezing my hard dick between her back and my stomach.
"I'm going to have the cleanest tits in the world if you keep that up, young man." she moaned, putting her hands over mine. I slowly moved my hands down, over her flat stomach, my hands being drawn like a magnet to her pussy. Like she had shown me, I gently parted her lips, found her clit and slowly massaged it. She moaned in pleasure and reached behind her to take my cock in hand, matching my slow pace as she stroked me. I slipped a finger inside her and she almost jumped.
Grandma's head was tilted back, her eyes were half closed and she was moaning as the combination of the warm water on her body, my hands on her pussy, and my hard cock in her hand were all working together to get her more and more worked up. Within just a couple of minutes, she was whipping her head back and forth as she came all over my hand.
"Couldn't wait could you?" she asked as she leaned back into me trying to catch her breath. "Not tonight." I said wrapping my arms around her.
She turned around in my arms and smiled up at me. "Then let's not waste anymore time. After all, you haven't cum yet."
We quickly got out of the shower and dried each other off before practically running to the bedroom. We hopped into bed and grandma lay down while I knelt next to her, slipping my fingers inside her while she grabbed my cock and started stroking it. We looked into each others eyes as we masturbated each other, smiling at our new bond.
"This is wonderful, but I need more." she moaned as I started rubbing my thumb over her clit in time with the fingers I was sliding in and out of her.
"What do you mean, grandma?" knowing full well what she meant, but wanting to hear her say it.
"Well... like I told you before, it's been a while since I've been with a man... not since your grandfather..." she trailed off and stopped stroking me, although she didn't let go of my cock. "Alex...?"
"What is it grandma?"
"Do you want to fuck me?"
Those were the words I had been waiting to hear. "More than anything else in the world right now."
She looked me in the eyes and smiled, "Then fuck me, sweetie. Fuck your grandmother."
I didn't need any further urging. I slowly pulled my fingers out of her soaking wet pussy, moved in between her legs and guided my cock in.
"I love you sweetie." Grandma said as the head of my cock penetrated her pussy.
"I love you too, grandma." I said as I slid the rest of my cock into her.
Once I was all the way in I didn't move. I just wanted to feel the warmth of her pussy wrapped around my cock. Not even my first time with Susan felt this good. Grandma looked at me. "Is everything okay, sweetie?"
"It's perfect." I said, "It just feels so good."