Beats me why Charlie didn't dump Tanya on the spot after that scene with Bet.
Surely he must have realised Tanya only wanted him to call into The Rovers so that she could follow him in and deliver that final cruel blow to Bet.
I don't think Tanya is an evil bitch, though. She's obviously somehow very damaged where men are concerned.
Her Dad has no time for her, and rejected her when she reached out to him a few weeks ago, and it was plain how much that hurt her.
She's desperate for a man to love her (maybe a father figure) but has no idea how to find or meet 'the one'.
I do feel sorry for her, really - she's just a very unhappy young girl underneath that tough, hard-as-nails (yet very brittle) veneer.