Why do you?
These people aren't supposed to be performing for your entertainment. They are living their daily lives which will be 90% boring, just like the rest of us. We are all sitting in front of our computers aren't we?
I think this is very strange... Stefan doesn't work hardly...he is at home for all the times... it's not possible he fucks Alma so few times!!! I think or they fuck in times that we aren't watching or she is not very available to Stefan! Several times in the late night I've seen Stefan jerking to a porn ! This validates the second hypothesis.
Alma isn't on camera nearly as much as Stefan, she knows how to hide I think