Jake's afternoon

Jake was dropped off by his mother, who waved and smiled as she drove off. Walking up to the front door of what seemed like an estate, Jake rang the bell and Mara answered it almost immediately.
"Emily! Good to see you, come in!" said Mara waving Jake in. She then hugged him, causing his breasts to press into hers. It felt...nice but also a bit uncomfortable.
"Let's get to the pool while the sun is out. Com'on upstairs so we can get changed. Mara started going up the stairs, and Jake followed with his eyes just the right height to see her curvy ass. He felt his nipples get hard again, and stopped looking as much. They got to Mara's room and Jake put down the tote bag from his shoulder. It felt good to get load off.
"So, Emily, I was thinking pool first, then maybe some time at the mall before dinner. What do you think?"
"Sounds good."
"Great, I'll get changed," said Mara going into the en suite bathroom and closing the door. Apparently girls don't change in front of eachother like Jake hoped. He started to strip down, about to pull his shirt over his head, when he realized he would have to see his sister naked. He had to do it though, otherwise Mara would catch on. He took off the shirt and took out the bathing suit from this tote. He put the top on the bed and stared it, hoping it would tell him how to put it on. He took out his cell and tried to find a youtube video, when he heard the toilet flush. After the momentary distraction, he saw to tie the top strings before putting it on. He tied the top strings and put it over his head, just as Mara came out of the bathroom. Man, was she hot.
"Having some trouble there Emily, here let me help tie your back," said Mara coming over to help. Jake turned around and let Mara tie the back. Jack took the bottoms and walked to the bathroom, "Be right out Mara."
"I'll get us some towels while you are in there."
Jack saw his, well his sister's, reflection. She was pretty and filled out the bikini well. He then shook his head and got to the task at hand. He looked straight ahead as he pulled down the shorts he was wearing and robotically pulled the string bottoms up. How could his sister own a bathing suit like this? How could his mom let him wear this? He then left the bathroom to see Mara come in with towels.
"Let's go enjoy the sun and the pool!" Mara hopped out of the room. Jake thought about how cute it was, and that he never saw that side of her at school. She was usually so serious. Jake walked quickly to keep up. Mara had some suntan spray but some lounge chairs and started to spray herself with the SPF 30. She then offered it to Jake saying, " can you do my back?" as she moved her hair. Jack sprayed some onto Mara's back and then rubbed it in. It was his teenage fantasy to do this. He felt the tingling in his breasts again, and stopped rubbing his sister's friend. Jake sprayed himself and put the can down. He was rubbing the stuff in when he felt the spray on his back and Mara's hands started to carass him. His breasts tingling and he felt something in his groin. He start to think about male gay porn, but found that made him this about penises in general, which got him back to Grant's dick. There was more tingling in his groin and he felt it get a little...enlarged?
"Earth to Emily, what's going on over there. You spaced out."
"Just lost in thought, you ready?"
"Sure am, " replied Mara spreading out her towel on a chair then lying on her stomach. Jake followed her example, but took a little longer to get comfortable with his breasts in the way. Mara took out her phone and set a timer. She then relaxed. Jake did the same, as best he could. He found his thought cycling between Mara's figure, Grant's penis and his breasts. It was frustrating, but Jake couldn't figure out all the reasons why. After the alarm went off, Mara turned over, and Jake did the same.
"So, are you going to ask Grant out?" asked Mara while taking off her top.
"Maybe," blurted Jake staring his Mara's breasts, getting that now familiar tingling.
"Well, you prude, you should ask him. I think he's interested. Are you going to take your top off Emily?"
Jake sat up and looked at Mara, who blinked at him. Jake, with some trepidation, took of his top and let his sister's breast into the open.
"If you ask Grant, I'll ask Jake. I've had a little thing for him, but I was afraid to ask because he's your brother," said Mara lying on her back.
"Really? Jake?"
"Yes, Jake. He's a little goofy, but sweet. He also works out a bit, which shows. I think he does OK in classes."
"He's almost getting straight A's, " said Jake lying back and feeling his breasts settle. He saw Mara set another alarm.
"Well, I think he's cute, and I'll build up my courage to ask him, if you ask Grant. I have it on good authority that he wants to go with you. I also have it on good authority that he is well hung"
Grant's penis flashed into Jake's mind, causing another little tingle in his nipples. He wished that would stop when he thought about Grant.
The alarm went off again after a bit more sunbathing, and they turned one more time before they went for a dip in the pool. After swimming, they used the outdoor shower and went back to Mara's room to get changed. Again, Mara went in the bathroom. Jake got changed before Mara got back in the bedroom. The girls got into Mara's Jeep and they went to the mall. Jake was initially worried about spending time in the mall. He started mainly enjoying what Mara wore. After a bit, Mara coaxed him into trying on a couple shirts. Then some shorts, and even got Jake into a miniskirt so they could take a picture together. Whenever Mara asked for Jake's opinion, he always replied "It all looks good on you."
After a couple hours, the girls went back to Mara's house and had dinner. They watched the first of the Terminator movies, then they changed into pajamas and fell asleep while watching the second one.