He could ask Ray to come with him. She might even say yes, and both he and Mel would appreciate some more company.
But, he realized, it was a recipe for disaster. However much she thought she loved that little motorcycle of hers, she’d inevitably fall for his TARDIS. She’d want to wire up buttons and tinker with circuits. And the old girl would be flattered—probably welcome the opportunity to make him jealous (and of a human!), after the way he’d carried on with dear Bessie, all those centuries ago.
Goodbye, Ray, he decided. Enough broken hearts here already.