The Truth Is Out There... and It Hurts - S1-E8
Piper: Leo, how do you feel about women who make the first move?
Leo: I don't know. I'm still waiting for it to happen.
Piper: Goodness.
[Piper grabs Leo and kisses him.]
Leo: How do you feel about guys who make the second move?
Piper: Love 'em.
[Leo leans in and kisses her.]
Answer: That was a mistake in the series.
Also, the episode is called 'Babies First Demon' and this alone tells us that it's Wyatt's first time in the field (so to speak) and as the sisters say, they've done a good job of clearing up their own magical messes so far. Nobody really knows how advanced Wyatt's powers are, or will become. That's why the cleaners appear, to nip things in the bud. The Cleaners didn't want to chance that the sisters could clean Wyatt's magic up, just incase they couldn't. Therefore intervening themselves, just in case.