A JC for dating a worldly guy?? Really? I mean, I've heard of a Shepherding Call and counsel for that, maybe even a talk about marking, but possible DFing? That's ridiculous! So while the admonition to "marry only in the lord" isn't broadcasted as a strict command and merely a suggestion, if you go against it, you're brought up in a JC? Jeez, the control goes deeper than I thought! They give people the impression that they have so many freedoms, but really, there's a cultural undercurrent of what's accepted and what isn't. It may not be printed in the literature (cause that gives the WTBTS deniability) but it's understood that this is how it's done.
I know a sister who got an "unscriptural divorce" from her worldly husband (she knew he was cheating, but she had no proof and he refused to admit it cause he knew the JW rules about remarriage, even though he really was screwin' around). She met a worldly guy and started dating him. A couple months later they got engaged. Very soon after that, she broke it off with him because he did something she didn't like, and she very quickly took up with another worldly guy, got swiftly engaged and married him, and she didn't get a JW, but a talk was given on marking.
I've never been brought into a JC for dating a worldly guy, even though I have done so in my late teens/early 20's and the elders were well-aware of it.