Theresa is feeling out EVERY man in Salem. It is almost as if the writers do not know what to do with her. They are pairing her with every guy and waiting until they see what the audience reaction is, or who they think the viewers like her with best. Next thing you know she will be paired with RAFE!!! Just pick a guy, and start a storyline already rather than having her throw herself on every male that comes within an inch of her. Personally, I do not even think she is attractive or a very good actress to begin with. They could have cast the role much better to make it more believable that she can even have the pull to get any man she wants.
As for her and Dan... well are the Writers REALLY that uncreative!!! In the last year the ONLY storyline Dan has had is one that involves girls becoming OBSESSED with him. Come on, it was Chloe, then Nicole and now Theresa! (I feel like I am even missing a couple ladies in the mix). Maybe throw Marge Bernardie in the mix. She is down and out and in need of rescuing which seems to be what turns Dan on the most. It would be perfect! (BTW, j/k on Marge, I was being sarcastic).
At least recycle a different storyline for him from a different character. Maybe give Dan another kid he didn't know about, or another life threatening illness, or Stephano is his father storyline. ANYTHING but another obsessed lady! Dr. Dan is nice looking but sheesh... you'd think he'd run & live with the monks away from all females with the luck he has had, lol!