He reaches that conclusion simply from the disapproval of this one person, which makes him believe that he needs a break from the others. Without looking for Ariadne, Theseus heads off into the trees. She comes with Theseus only because she seeks her freedom, does she not? Thus, the two of them need not be together at all times. If she wants a more devoted companionship, then... Ariadne will have to look elsewhere.
Even as he thinks this, Theseus is unaware of his own cruelty. Would his father been here, perhaps he would've scolded the prince and encouraged him to be kinder. But Theseus has been without a female influence for so long now.
Will... his father be pleased that he's found a bride? King Aegeus has certainly noted in the past that Theseus has not yet taken one, but he's never seemed to concerned by Theseus's lack of interest, believing that, in time, the right woman would come along. Given how intelligent and confident Ariadne is, Theseus has no doubt that his father will approve of her as Theseus's wife.
Now if only Theseus could approve of her as Theseus's wife.
These thoughts weigh heavy on his mind and, before Theseus realises, he's deep within the forest that he wandered into on a whim. The prince fears not this path, knowing that he can retrace his steps when he needs to. If anything, the thought of being alone here... somewhat excites him. Naxos is known for its giants and, after the disappointment that was his one night with Heracles, Theseus wouldn't mind laying with another giant. Perhaps a more ruthless one, who would treat him roughly...!
He rests his hand against the knotted branch of a tree to steady himself as these thoughts consume him. By now, the prince has mounted quite some experience with half-beasts in a short time, but the thought of new opportunities still send a rush through him. He is aware that he is addicted and yet, he cannot stop.
