Prank him

"Hey, Garrett?"

"Yeah, man?"

"I don't think you brushed your teeth this morning." Garrett looks at you with a look of shock,

"I think you're right man, thanks for the save." He started to walk over to the bathroom, when you say,

"Hey don't worry bro, I got you a new toothbrush right here." Garrett looked at you a little confused.

"New toothbrush? I don't see anything."

"Oh, that's because it's in my pants." At this you whip out your dick. You expect him to have some sort of hesitance, but he seems to believe you.

"Well that seems like an inconvenient place to keep it," he says as he walks over and pops a squat.

"Well, it generates its own toothpaste. You just have to stroke it a little." Garrett reaches a handout and begins stroking your dick. His warm hands feel nice against your cool dick. A bit of pre-cum leaked out the top.

"Wow, you're right." Before you can stop him, he shoves the dick in his mouth, rubbing it against his teeth. His pearly whites feel jagged against your dick and you shift a little.

"You just suck on this toothbrush and it cleans your teeth that way. It might help to scrub your tongue as well."

"Oh... dang science is wild." He wrapped his wet lips around the shaft of your cock, sucking it more vigorously, although occasionally pausing to lick your head with his tongue. He begins to suck a little more, a little faster. You can't believe that this is happening. He legitimately believes that your dick is a toothbrush. He was surprisingly really good at giving blowjobs, you could feel yourself blowing your load any moment.

"Alright Garrett, get ready for a mouthful of toothpaste." Garrett made a sound of an acknowledgment as he continued sucking. You were about to cum any moment. "Unnnngghhh," you moaned as you dumped your load in Garrett, who hungrily sucked it off. You pulled your dick as Garrett began to swish your cum in his mouth. "Hey Garrett, don't you want me to have some of your toothpaste."

"Sure bro," Garrett got off his knees and his face was inches from yours. He began to make out with you, transferring the cum-saliva mixture into your mouth. Your tounges slide around in each other's mouths, cum leaking from your lips. What felt like too soon, Garrett pulled away, "That should be enough for you to brush your teeth with." He then proceeded to the bathroom and spit out the mixture, gargled some mouthwash, and then returned to organizing his clothes.