Honestly them doing it would be fine, nothing graphic needs to be shown, just the insinuation (an example is Horimiya). Tbh them thinking about it and mucking up in some way would make a lot of sense too. Id be more than happy he just stays over the night sleeping in the same bed as her, would be cute.
Hopefully no 'interruption' because Id rather whatever their plan be, it be from their own conclusion, not a forced one by an external source like her Dad having a change of plans or whatever.
Also I'm so glad they aren't actively ignoring each other because of that stupid idol stuff now.