The other possibility is that he is being pushy or more direct by snuggling with you and that she is avoiding conflict by keeping away from both of you. I see this with my two neutered males from time to time. I think though, just by virtue of male-female dynamics and by her being the older of the two, she would put him in his place quickly if that was the case.
Regardless, if neither of them is grumbling or posturing over the subtle shift in household dynamics, I'd just leave it be and enjoy watching them be dogs.
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