Do Businesses Have the Right to Refuse Service Based on Moral/Religious Objections?

[betenoire]

(2) For any practice mentioned in paragraph: (1)(g) to be considered to have a bona fide justification, it must be established that accommodation of the needs of an individual or a class of individuals affected would impose undue hardship on the person who would have to accommodate those needs, considering health, safety and cost.

There's your answer right there. Selling flowers to a gay couple wasn't going to effect the health or safety of the shop owner - and it also wasn't going to profit the shop keeper any less than selling those same flowers to a heterosexual couple would.