I love the title of this thread. It's sweet to see the tenderness of the body recognised. I do become weary of the smash it, bash it approach.
To answer your question, yes I've experienced this. It happens to me sometimes during Yin Yoga especially during upper back and chest sequences that involve the heart. It usually takes me by surprise and I rarely know why it happens. I simply let it happen. It's a release and it feels good.
Here are some thoughts from Esther Ekhart. She is writing about Yin but I think it applies more broadly to anything that puts us in touch with our shadow side.
Yin Yoga and the mind
Becoming still in a pose and staying for a while, creates those gaps that I was talking about earlier. Keeping the gaps empty creates the space for anything that wants to come up. For example, feelings of anxiety, feelings of happiness or sadness, boredom. Anything you suppress with all the on-the-go busyness in your life. Finally, you take time out to allow for any of those feelings to be there. Emotions, thoughts, feelings we have kept in the shadows.
Generally speaking during a Yin Yoga class the teacher will encourage you to allow all those feelings to be there, but not identify with them. The teacher will guide you to become the observer of everything that arises in that space. All those stored away emotions, feelings and sensations now have a chance to come out. You have no idea how much energy it costs the body to keep all that suppressed. So the release you get from letting it all come out can also be just as big.
You learn to observe only the pure physical sensations of emotions, without getting caught up in the stories about those emotions.
These stories usually have to do with why we feel such and such, whose fault it is etc. Just observing these physical sensations, without giving juice to the stories allow those emotions and physical sensations a way out of your system. You open the door in a way of speaking.
This way you clear the mind of these often unconscious emotions, and you give your system an opportunity to work through the blockages they have caused in the body. What a wonderful and much-needed process!"
The whole article is here:
https://www.ekhartyoga.com/articles/the-benefits-of-yin-yoga (The benefits of Yin yoga – Ekhart Yoga)
I consider these moments to be beautiful and a part of making us whole again through a body-knowledge that heals and integrates on a deep level. I feel it is wise to trust it, to lean into it as you say and believe that something magical is happening. The mind forever wants to have all the answers and be in charge but with this it has no chance. This is all about surrender and letting go which may be two of the minds greatest fears.
Love to you,
Plum x