as idea to improve the performance, especially on slower devices
you use "show" to display full screen images and animations. this renpy function adds the displayables to a layer and never removes them from the scene, they are still in memory and active, just hidden behind the next full screen image/video you show.
this is mostly noticable in the sex scenes, the more videos you show the slower everything gets (my poor old couch laptop stutters a lot when the third animation is started and the two former ones are still running, only invisible)
using "scene" instead of "show" has the same effect as you only use full screen displayables, but "scene" clears the whole screen and removes the former images/videos from the active layer and they are not kept in memory anymore.
this does not matter a lot for static images but on my device rather important for animations - your original variant with "show" was a stuttering mess, displaying the videos with "scene" instead smooth as butter.
as an example, from chapter2.rpy starting around line 720, my changes marked with '# was "show"'
hide screen disable_Lmouse
image mne_ch21 = Movie(play="anims/chapters/chapter2/mne_ch21.webm", loop=True, xalign=0, yalign=0)
scene mne_ch21 with dissolve # was "show"
melinda "This sensation..."
melinda "I..."
melinda "I just can't resist it"
image mne_ch22 = Movie(play="anims/chapters/chapter2/mne_ch22.webm", loop=True, xalign=0, yalign=0)
scene mne_ch22 with dissolve # was "show"
melinda "The way it feels inside my mouth..."
melinda "I like..."
melinda "I like this so much!"
image mne_ch23 = Movie(play="anims/chapters/chapter2/mne_ch23.webm", loop=True, xalign=0, yalign=0)
scene mne_ch23 with dissolve # was "show"
melinda "I must hurry!"
melinda "Annie or Momo could be here at any moment!"
when you want to keep the better control of "show" with its layer management you could opt to "hide" the animations before the next one is started, this removes them from the active layer and they are not kept in memory anymore. don't think you benefit from it, though. a lot of hassle without great advantages, imo.