It is very clever my friend, and I got exactly what you are saying but a small concern here: The second sentence connecting through the "But" doesn't establish any "But." It only establish some kinds of double meaning to the word wall and side which adds a very clever perspective. So I would change "But when" to " Yet then" But your decision, just a suggestion. I might be wrong.
Dear Walter, this is the second time I am trying to establish a critical- creative bond to your Senryus, if I again sense you do not like this kinds of constructive bonds, I would never bother you again.
Smartly penned.

I am so happy now because I've found a good man. Love you my friend.