The dirtier side of lawn mowing?

I spent years writing limericks and forcing them into meters that didn't quite work. Here, you switch meter here and there. The one you use on the second line is actually the proper one. Rhymes are all clean. Not really anything else to say, as it's a straightforward joke. Amusing and a pretty good effort.

I found this pretty confusing. It speaks both to the general problems of aging, but then it also seems like the narrator is sick, so I'm not sure how to take it. And I don't understand what he's spreading wide at the end. Is he contagious and either shrugging off that me might infect someone or hoping to do so intentionally? The last two stanzas have a fixed rhyme scheme, but the first two are erratic. The first two lines rhyme somewhat, but that may have been unintentional, as the second stanza is identical in form yet doesn't do this. Be careful what expectations you're setting up about how the structure will go.