"Let's shower at home. I forgot that the water pressure here is not that good." Mike said, hoping that Zack doesn't call out his lame excuse.
"...Okay." Zack said as he follow Mike to his car.
Mike took off his shirt as he got into the car, showing off his huge pecs and sharp defined eight-packs. Zack widened his eyes as he got into the passenger's seat, goggling at his brother big guns flexing as Mike starts the car and holding the steering wheel. The pendant hanging from his neck just accentuate Mike's body, making it hotter. "I need to cool off after that workout. You can take off your shirt too, you know?" Mike said, trying to hold back a smirk,
"I'm good." Zack said, trying to look elsewhere. His shorts starting to tent without him knowing.
The drive back was full of sexual tension. As Mike pull his car up the driveway, Zack was ready to bolt up to go to his room.
"Hold up, Zack! I need to talk to you." Mike stopped him from going immediately.
"What is it?" Zack said, trying to be patient. Trying to cover the hard-on he has right now.
"Let's get into the house first."
Once in the house, Mike faced Zack and holding the pendant between his finger. "I love you as a younger brother and you trust me as a big brother. So you would tell me truthfully what I ask alright?"
"Yeah..." Zack said.
"Have you ever wanted to have sex with me?" Mike asked, showing his bulging shorts proudly, not that Zack's attention is there.
"...yes, you were so hot." Zack said, his shorts too were bulging.
"Strip," Mike command.
Zack took off his shirt and shorts. Revealing a buff physique, his previous pudgy body were gone. All that's left is pure masculine muscle, not as defined as his big brother but bigger. His cock were an average 5 inch and dripping pre-cum.
"That's not humanely possible...losing all that fat that quickly..." Mike mumble to himself. "Zack, you're so turned on right now that you're brother is going to have sex that you can growing harder, and bigger and longer. You're able to touch yourself but not your cock." Mike decided to try something.
After Mike finished talking, Zack begins to fondle his balls with one hand while the other fondling his pecs tweaking his nipples. To Mike's surprised, Zack's cock really did grow as Zack moaning from how turn on he is. His cock grew another 3 inch before stopping, and it's so thick that you can barely hold it with one hand.
"Do you want to have sex with me?" Mike asked, not being able to hold out his lust much longer.
"Yes. Big brother." Mike's cock jerked once as he hear Zack called him big brother.
"Then come to my room and let's explore your fantasy." Mike said, he didn't want his father come home to find his sons making out in the living room, at least in his room he can hear if his father came back.