I wonder if the editing is making it look like Callum will stray, when potentially he might not. I can't call it. I get he wants to, the question is will he.
Molly looks younger, maybe prettier, depending on your view, and is slimmer than Shauna . For someone shallow Callum that might be important. The mans never had a relationship and slept with over seventy women, so it would seem that sexual gratification is where he is at.
And he ain't going near Shauna in that way, let's be honest. He seems unable to keep it in his pants but manages just fine round Shauna.
I honestly couldn't predict what he will do as I think if there were no tv cameras, he'd have been in with molly immediately. The cameras may change things, he will know he stands a better chance of winning with Shauna.
I also hate to say it but in real life molly wouldn't have given him a second look, he'd have stood no chance, but I suspect Shauna would have. I'm not sure he'd have went near Shauna though, I think he likes the younger, slimmer, overtly sexy thing. He's not really looking for s woman with a bit of personality who can stand her ground.