Leeching.

but if someone offered free leech or just a few hh leeches whilst you chill with them.
is that so wrong

Well, I would have to say it's not totally wrong. You're not just sitting there getting EXP for nothing, you're spending time with a buddy. Assuming that's not the only way you train, I wouldn't say it's extremely bad. You're not sitting there for 4 hours while he kills HH, are you? You do level your character by other means, right?

This is a similar case to me going to Papulatus with a 14x guild mate. Yeah, I hit the thing a couple of times and got a small amount of experience, but he did 99% of the work and mostly I was just trying to stay alive. (I failed, BTW.) Did I get some EXP from it? Yep, although I lost it later due to dying. Now, you can't just hang on a rope at Pap, but if I had survived I would have gained 5% or so from that (I think). So, you could view that as leeching, from a certain point of view.

Hell, I don't even see Priests as "leeching" if they are with a party and doing nothing besides providing buffs and healing -- after all, that's why we have Priests, isn't it? They get some EXP from healing, they benefit from Holy Symbol along with everyone else, so as long as they are actively contributing (not botting) I've got no problem with that. Some people say that Priests do nothing but leech, but um... it's called party training.