It's a valid reason. By and large she's accepted that secrets can't be kept from their employer-- not for long-- but she's past the point of wanting to flaunt their relationship. Not that she's trying to keep it secret; she isn't ashamed, just uncertain. A little privacy is welcome, though.

She doesn't pull away.

"I suppose it has to; it snows in summer, here." She isn't looking at him, eyes on a branch arching above them, heavy with star-shaped white flowers. "I almost hate to admit, there are some nice aspects to this place." She pauses, casting a sidelong glance his way. "Midwinter flowers. Unicorns."