Is this sentence ambiguous?

Can someone please evaluate this sentence for me?

"Rob's feet smell like flowers on a Spring day."

I was joking around with my cousin and I wrote this. His reply was the following:

"What do they smell like during the rest of the year?"

He wrote this to point out the ambiguity in the grammatical structure of my sentence. However, I fail to see how this sentence can be interpreted both ways. Please let me know whether or not this sentence is, in fact, too ambiguous. If so, I would appreciate any clarification as to what is wrong with it.

Thank you.

Your cousin is being witty.

But, I don't think that he is formally correct.

"Smell" is present simple (habitual, repetitive), so it seems to me that for formal correctness it should be "on spring days."

"Rob's feet smell like flowers on spring days."