But if we do not associate with non devotees how can we preach them for spreading krishna consciousness sometimes we have to go in their association so they can develop taste for holy name.

Usually karmi people talk about sense gratification about men, women, TV, newspapers, ....so that time we should not join them in those talks but we can suggest them to talk about Srimad Bhagavatam of about Krishna Conscious philosophy. Or at least we can teach them how to cook vegetarian food, explain about Prasadam, ...we have to give them our association. Which means talk about Krishna and things connected to Krishna.

But when things go far from Krishna then we should be silent and go aside.