I did Daniels Mass Building Lower Body Workout (https://www.fitnessblender.com/videos/mass-building-lower-body-workout) yesterday and was really in the zone, breathing hard, feeling the burn, all the good stuff and was so nice and relaxed by the time the cooldown came around I just didn't feel any stretch whatsoever during the "Wide Leg Center Stretch" (standing with feet wide and leaning forward) I was like "well, lets go down a little deeper" but instead of a little I kind of slid down (slippery, sweaty feet!) further and further and suddenly I was sitting down, comfortably, in the side splits. oo
Just for reference: I've always been relatively limber and can do a forward split without having to stretch at all but the last time I was able to do a side split was... 20? years ago, probably. XD But then again, I have never been able to maintain this level of activity I've currently going on, so it would make sense. Still: holy moly, side split. XD just tried it again: would probably have worked if the soreness from yesterday wasn't setting in.
I'm officially as flexible as I was when I was a kid. YAY. :D