It has been said by numerous people on numerous times on numerous pages and by VH themselves, that nobody can make the tenants do anything they don't want to do and if you're not happy watching an apartment for any reason, then you simply don't watch it. There's literally nothing more that needs to be said. There isn't even a counter argument for this.
As for Bob visiting, normally this would be exciting but remember when Logan the last time? Em barely said a word to him. And then he was never seen again. Bob visiting may add some new dynamic to the apartment for a little while but that's still no reason to expect anything sexual or dramatic.