In his senate years, Ted "lives" in Washington DC and Heidi in Texas. At times before that, it was reverse---Ted lived in Texas as Solicitor General and Heidi in DC working for Bush. So when the cat's away...He would have had plenty of opportunity.
Google around or look through my previous posts---I have posted a whole lot of info and links on Heidi---there's an interview with Heidi where she says the daughters refer to Ted, when he comes home from Washington for the weekend or whatever, "the guest."
Heidi has said she has a nanny, maybe more than one, so probably during this campaign she's maybe able to keep an eye on Ted's roving eye more.
I do believe this is not new behavior for Cruz at all. Character is kind of a life long thing but the ladies shown are probably from the past few years.
I believe that there exist rich and/or famous people and/or politicians who have gotten in trouble for doing the baby sitter, though I confess at the moment I cannot recall any specific names.
IF these rumors are true, then it might be fairly said that the United States is finally becoming more like Europe, just as the Democrats have been pining for, for a long time.