I have at least 3 of my ex who I know did it, and now I suspect a new one.

Are they hamstering it as non-cheating because there's not cock involved?

When suspecting, are there known signs? Any known ways to test or probe her?

Keep in mind that I consider this girl a potential LTR before telling me to next her. I'm getting old and need a girl to breed some womb nuggets.