Days of Future Piff
Superstar
that was after she was already activated, he didn't want to murder her. the fact that he could have feelings for her was evidence of her humanity.
but if i recall he was the only one advocating to destroy them before they were ever activated.
This is actually true. He wanted to deactivate them in advance, but Goku and Vegeta were against it. Vegeta threatened to kill anyone who deactivated them in advance, as I recall. Later on, Vegeta willingly LET Cell absorb 18 for the sake of a better fight, and a chance to show up Goku.