I’m pretty sure context and inflection would probably make a huge difference here. You may say 触ってもいいですか, but if you are entering someone’s home or going out to eat and approaching a table, I think they’re going to understand your intention or at the very most that you made a silly pronunciation mistake.
I was once wondering around a neighborhood in Tokyo and passed by a group of friends who were saying goodbye to each other. I heard one of them say "お疲れヤマ". I stopped, wondering if it was some strange kind of slang or regional variation, but she then started laughing and said "お疲れマウンテン".