I think Mark and Sarah are done with... once Hank kissed her that sealed things IMO. She was already obsessing over him (which Mark already realized) and I was kinda surprised Mark didn't question her somewhat turn around on moving in together. Mark is a stand up guy and has been super patient with Sarah but he's gonna end up broken hearted Poor Drew is so messed up but then again having flighty Sarah for a single-mom hasn't help him! LOL! He's been really direct about how he feels about things. He may not be up front about it but when he tells you how he feels he puts the truth right out there.