A semi in British slang is a partially erect penis. I guess “atomic semi” would sound like “partially erect micro-penis” to a Brit.
I couldn't decide between micro-penis, and some kind of comic-book hulk type appendage. But your description was very eloquent, so I'll go with that.
I couldn't decide between micro-penis, and some kind of comic-book hulk type appendage. But your description was very eloquent, so I'll go with that.