Why are consecutive sessions always worse? Does anyone else experience this?

I typically play with my Aneros most Friday and Saturday nights. Almost every weekend, I have an amazing session on Friday night and then a lackluster session on Saturday night.

Has anyone else experienced this?

I have a couple of theories 1) I usually end my sessions by ejaculating. Maybe the 5-6 days without ejaculating makes my Friday night sessions better. 2) I typically end my sessions with a vibrator, helix syn. I know vibrations can desensitize, but I would think that would go away after 24 hours. 3) Expectations. Now that I have noticed this trend, could I be manifesting it by expecting my Friday sessions to be good and my Saturday sessions to be worse? 4) In the moment, I often find myself comparing the current session to the previous one. Chasing the dragon, trying to achieve the highs that I experienced the night before, instead of just existing in the moment.

Honestly, none of these are very convincing to me because I have tried not ejaculating at the end of the session, I have avoided the vibrator or only used the lowest setting, and I have had sessions where I was mostly in the moment and not comparing, but the trend almost always still holds.

Is this a typical experience? Any ideas for making both of my sessions amazing?