>>29360745>>29360771Even pokemon that aren't caught can understand humans. That's how Pokemon Rangers, Park Attendants and the like all handle pokemon in large numbers that aren't tame. It's like being around people who speak another language and picking some of it up but not knowing enough to be able to respond.
Captured Pokemon do have the balls to make them *more* obedient, but you have to earn respect to make them obey. They aren't obligated to listen just because they're in a ball. This is why the games make you collect badges to have pokemon of higher levels obey you. Yes the rangers have the lassos to try to help, but lassos fail without respect. The badges represent trust and respect. One of two NPCs in each game tends to mention pokemon requiring respect to make them listen.
If you want to count the anime in as "lore" there's lots of examples of Pokemon that aren't obedient. James' Victreebel tried to eat him many times. Jesses's Wobuffet didn't obey her at all for most of the XY series- he listened more to Meowth and did whatever he wanted for the most part. Ash's Charizard attacked him regularly.
You would need to either have a consenting mon or mentally/physically abuse them into having sex with you- just like with humans. Only these guys can breathe fire and spit acid so the bad guys are going to have a harder time of it.