He knew right away that you came here to turn him down again! When his eyes landed on you at the gate, he could tell just by the way you looked at him. That wasn't part of his plan. Aseph will get you and keep you no matter what. That's why he invited you horse back riding, he'll listen to you while going for a stroll in the forest....or not.

He came prepared with a poisoned needle, the moment they were far enough, Aseph didn't hesitate to use it on the poor animal. It was a small price to pay to get you, right? Aseph knew very well how to play with people's feelings, how to act all helpless and hurt.

"Can you please help me bandage my shoulder?" He winced in pain, knowing he'll elicit a reaction out of you in no time. He'd be damned if you slipped through his fingers, that wasn't an option in Aseph's mind. You don't even understand what extents he'll go through to keep you. If a bit of acting keeps you to his side, then so be it.