omfg awesome pun! But I kind of get you like...it's weird...I think my normal fears would earn my significant other a good punch too, but phobia wise, it's like an extreme adrenaline rush/ waterfall of emotions, not just fear, which may be why it's different. Idk, someone prob gonna leave a comment like 'you're glorifying phobias!' but I'm not, I'm just trying to explain my mentality lol.
Have you ever seen the movie "Secretary" with Maggie Gyllenhaal and James Spader? The character structure is inverted in that it's Maggie's character who introduces cockroaches (and big, fat earthworms) into their sex play as a very specific kind of provocation. And it works ... for her ... ie., some fellas would probably find threats to their little friend exciting and look at it as any attention paid to their cocks is better than none at all. (Just something to keep in mind if you ever wonder why servile, supplicant, misbehaving little boy-types seem to be attracted, or if your lover presents you spanking paddles.)
As someone with an actual phobia, though not mysophobia, I find this manga incredibly intriguing. Especially because, after thinking about it, I'm a total sub but having my partner make my fear go off the charts would be fucking terrifying-but also exciting in a weird, fucked up way.