Your high school dropout neighbor

A certain individual pops into your mind. Someone you're fairly familiar with but whom you won't feel any guilt from using him as test subject.

You immediately start crawling stealthily through the floor, taking advantage that your whole family is dining in the living room to slip under the door and get out.
From then on, you keep moving through the neighborhood, favouring the corners and hiding in the shadows, making sure no one notices the living red goo slithering at ground level.

Despite your relative closeness, it takes you almost an entire hour to arrive to your destination, and you realize how draining it is for you to be out by yourself, exposed to the weather.
The quicker you enter a living body, the better.

After making sure no one can see you, you advance through the back of the building, dodging plants and grass, until you reach the roof drainage pipe. Then, you use it to climb up to the roof and quietly move to the position under which you know is your objective's bedroom.

And with a quick peek through his window, you immediately find him. He is in his bed, taking a nap in the middle of the day. If you were still human, you'd be rolling your eyes. 'Who would've thought?'

This lazy ass is none other than Kevin Simons, a guy one year younger than you with whom you used to be friends back when you were kids. However, as you both grew up, your personalities started to clash, and you kept growing distant until you stopped meeting altogether.
You've always attributed that deteriorating relationship to Kevin's many issues. Like being a very sore loser, lacking initiative for anything, always telling both his and your mom whenever things didn't go his way and being a toxic crybaby in general. He just never seemed to give a shit about anything that wasn't him or didn't give him immediate gratification. And as a result, he even ended up pissing off many people and even dropping school.

Overall, Kevin is the perfect individual to test what your new form is capable of.

While being very careful not to fall, you slowly climb down until you're finally entering through the open window. This is a tense moment, and you become extra careful not to make any sound or sudden movement while you advance forward until you finally get in position over the bed.

In front of you, the imposing figure of Kevin is lying on his side while facing the other side. It's not like he is a big guy by any means. Actually, his physique is rather lanky. However, from your newly reduced point of view, his sleeping body looks like that of a giant.

You look around for a moment to see if there might be any interruptions. But the door to this messy room is closed, and it even has a latch on it.

Alright... -you get your attention back to Kevin- ...which hole should you use...?