Friend is 35 I don't know?

My friend is 32 and he dating a girl way younger then him. They both definitely in love I can definitely see that. She 18 how do other feel about this? Him being 35 and she being 18. I always had a open mind, but 18 i know what most of u will say well she now old enough, true but tbh I got mix feelings about this.
Friend is 35 I don't know?
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