Oliver let go of her hand lest anyone see them and taking her properly, elbow in his, led her to the balcony, trying his best not to look so affected. He scanned the balcony and thought perhaps, if anything, he could force Lisa to apparate him to London if he had to get away quickly. There were several brooms parked near the front gate, but he knew that running around the house with Aurors on his tail was something he'd rather not chance.
Reaching the balcony, he smiled down to Lisa (as best he could, given the circumstances,) before looking out over the gardens. He sighed a bit and cleared his throat.
"That was terrible," he said softly, hoping it was a neutral statement. She'd either thing the brand was terrible or the girl was terrible, and it would help him better judge her feelings. He secretly hoped, and was rather sure, she would be an ally to him and he hated to admit it, but he'd be upset if she wasn't a Muggle sympathisers. She seemed to kind and genuine to be a Purist, but he could always be wrong.