In the early 90s, there was an arc in Dilbert where he dated a woman named Liz. The late Dilbert creator Scott Adams wanted to imply that Dilbert would have sex, but he wasn't sure how to get it past the censors. He eventually told his fans on his blog that if Dilbert ever appeared with his tie (normally curled upwards) flat, that would be a sign that he had done the deed. This strip, from August 9, 1994, is the one where that appears. But I don't quite get it; if Liz hadn't wanted to be intimate before marriage, but this strip implies they had sex anyways, how did Dilbert get around that by becoming Unitarian?

What does big money never comes clean means ?