Context.
I think a lot of this comes down to context. Yeah, most cartoon tickling is between two kids, but there's the rub. It's a cartoon - generally they ARE for kids. I guess people don't make these things with tickling fetishists in mind, if you get me 🙂 It's just a kids thing, that's all.
What we have to remember is that tickling doesn't mean the same to most people as it does to us. It's harmless, innocent, inconsequential. Monkeys, especially chimps, tickle each other frequently - it's a social thing for them, and for humans alike. It's an interraction, backed up by the "you can't tickle yourself" thingy. But for most of us here it's a turn on.
For me, so long as you aren't tickling kids and getting sexual gratification from it, then that's okay. Parents tickle their kids plenty, it's okay. But I agree with Camel about underage tickling for sexual gratification or satisfaction. It just doesn't sit well with me. I'd not hesitate to take a baseball bat to anyone who tickled a kid I know for sexual satisfaction. I'm sorry, but it's how I feel.
This is a really awkward argument, because there are so many facets to it, such as how young is too young (USA age of consent=18, UK=16), in which context kids tickling kids is produced (or a grown up tickling a kid, or whatever), and also whether it's wrong or not. So far as I'm concerned, underage tickling of a sexual nature is wrong. As in most cases, so long as nobody is being hurt, harmed or damaged (potentially or otherwise, mentally or physically) then I'm generally okay. But I respect the law on age of consent, and 18 means 18 - not 17 years and 364 days old.
Sorry for the rant guys, but I'm very much against taking advantage of people, especially if it's kids or rape or whatever. It's the same thing with my tickling - I wouldn't DREAM of tickling a girl if she didn't like it, or if she had enough and asked that I stopped. It's about respect, I think. Obviously this is going to be very controversial...
Thanks.
Moondog 😉