Ways to surprise cousins wife

My cousin n his wife will be doing a South Indian tour with their two kids(aged 3 and 1). They will first be visiting Trivandrum and will be checking in to the Taj. Now he wants to surprise them with something nice as soon as they enter the room or after they go sight seeing and then come back to the room. He has no idea what to do but he wants to make them happy especially his wife and may be the elder one too. The younger one is too small to understand anything. Please tell me what can he do to suprise them. What can he ask the hotel to do(even if it costs soemthing). Please suggest some nice romantic ideas.

Thanks in Advance