Python 2, 58 bytes
-30 bytes by realizing it can be as simple as [Arnauld's JS answer].
lambda s:re.search('[^aeiouy]([^aeiouy]|$)',s)<1
import re
-30 bytes by realizing it can be as simple as [Arnauld's JS answer].
lambda s:re.search('[^aeiouy]([^aeiouy]|$)',s)<1
import re