It is what it is. Pay for it, or don't.
4 updates a month for a 2 person operation with family and other jobs, is a lot and anyone who says otherwise is off side. The last video combined, with people bitching here, tells you all you need to know about why they are not making new stuff - they're just not into it. "Tease" is a creative box and eventually it gets difficult to come up with new ideas within that box. Maintaining enthusiasm - both of the creators and the viewers - is also very, very challenging.
They have more explicit stuff, but judging by how careful they both are, I doubt there is a lot of it. Really explicit stuff is unlikely to be released. Of what they do have there is no incentive for them to release any faster than they have already.
This is the state of the world: accept it or pass on it.