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This is a tough question to answer with no more detail than you’ve provided. All we can do is guess and make references to when something similar may have happened to us, and what our experience was.
For example, without knowing what his reaction has been in the past when you have tried this (if you have), that may certainly play a part. If you’ve attempted to initiate affection in the past and been spurned – however little! – that would certainly be a turn-off, even if you wanted to act on the feelings that led you in that direction. But you don’t say.
It would also be helpful to know the culture you’re coming from (or his own culture, if different from yours), and whether that’s even an “acceptable” female response. In some places it’s not.
Is this something that you and he have discussed in the past? Is it a recent feeling? Did something change before you started to feel this way?