TIFU trying to hide my boner without using my brain

Throwaway account.

Last night my roommate (25f) asked me (20m) to rub antiseptic cream on her lower back. She had a bruise just above her butt from a recent accident that involved too much alcohol and too many stairs. She was wearing an arm sling too. I was warming my food and finishing my weed when my roommate approached me and made her problem our problem. She indicated that her good arm was out of service and requested my assistance. I pointed out that nothing was wrong with her other arm though. I was joking. It was the stoner in me surfacing. I said tell me what to do.

My roommate unexpectedly leaned over the counter in front of me and lifted her shirt above her waist. Not gonna lie, inappropriate thoughts automatically crossed my mind at that moment. I'm human. However, I didn't allow my filthy imagination to cloud my judgment. My roommate instructed me to be gentle when applying the cream because the bruise on her back was still sensitive. I applied the cream as gently as possible, but she was wincing and groaning when I touched her. I was literally rubbing her the wrong way.

Mid rub, my roommate looked over her shoulder and said "just like that." It was unintentionally hot. I was unable to prevent my inevitable boner from showing up. For the record, I do not have a bazooka between my legs, but my sweatpants did nothing to hide my growing excitement. I was afraid my roommate would feel uncomfortable if she noticed, so instead of making an excuse to walk away, I panicked and switched off the light because the light switch was close to me and it somehow made the most sense at the time. There was no plan. No next step. Zero logic.

I didn't know what I was doing in the dark, it was dumb, I was high, but at least my boner was invisible. My roommate's first reaction was to quickly pull me close, too close, which I did not anticipate at all. She gasped and instantly backed away when she realized my rocket was ready to launch. I defeatedly switched on the light and awkwardly covered my boner with a random box of cereal. Honey Nut Cheerios. My roommate laughed so hard she was wheezing. When I was done using the box of cereal as my personal boner blocker, my roommate, who was still in stitches, used a marker to scratch out "Honey" in Honey Nut Cheerios and add my name. She's never gonna allow me to forget this.

TL:DR I tried to hide my boner from my roommate using darkness, a box of cereal, and none of my brain cells. Little did I know that the combination of darkness and Honey Nut Cheerios would make my boner even more obvious than ever before.