That's kind of funny -- in an 'I won't be playing Pleasantview any time soon' sort of way -- as Don Lothario's home is frequently my own little science club, and Don my lab rat. More biology really. He could have his woohoos, as long as they satisfied my curiousity about sim genetics. My most bred sim, he had over 30, to 30 different sims, in one of my earliest installs, but I never did get any 'memorable' spawn from him. Cassandra, on the other hand, spawned what would later become my pollination tech.
To get back on topic, if it were my game, I'd just remodel Don's lot to suit. Put in a few telescopes, ant farms, etc... Does the hobby instructor still show up? If so, it
might be salvageable, if a little fiery and ball-shaped.
Second thing I'd try, being fairly less awesome, would be to restart Pleasantview from scratch...
I'll have a look in my recently restarted Pleasantview. I think I'll use Don.
...
Don got in, went to the [correct] lot, went home again. I used 'Walk to lot...' if that makes any difference.