To be honest, I'm not even upset.
I'm more disappointed in myself.
This author has let it known 110% his dedication to sticking to a gag, so me expecting him to not make the MC do something stupid when he's literally at the finish line (choosing Sylphia when he's about to insert into Spica even though he literally casted a spell to never get soft so it didn't matter), not have an nearly impossible coincidence happen to prevent mc (why the hell did Lassen come to his fucking room in the first place naked!?), have mc suddenly stop and think in the worst possible moment instead of just going with it (Ya know you're going to get shot and you've already inserted and she shouldn't have even been there), and then of course have him be unconscious for the actual deed AND be premature.....because funny.
Yup, saw it coming but still had hope the author would just let it go.