I have solved my issues - thanks.
I had not finished content in the ? section.
It was weekend stuff and I had missed that you needed to go to the Library on Saturday morning - which was the only time I got to see the cheating brother. (It didn't work on Saturday afternoon or Sunday at all - is that right as I am sure the hint said 'at the weekend'?
Sunbathing only works on the weekend? Probably could have got there sooner when doing weekday stuff with Amy or Claire I expect.
I then found it is repeatable, which made me wonder why you hadn't made Selena's BJ repeatable - I know money will be involved, but she could be 'practising' and/or storing refrigerated semen for future use. Claire's sexual content could also be easily repeatable to help fill out the days.
You basically have 4 slots per day, and 'Night' at the moment really only has one event, so as the game gets more action, it will probably need some sort of choice of action guide.
Following my remarks about Saturday above, it might be useful to have options pop up?
For a simple hint something is happening such as:
'Go to Library'
'Go to Pool'
Or for a better hint:
'Go to Library - Claire's story'
'Go to Pool - Kate's story'