I think there are occasions when it is important to show up as the best version of yourself. I'll bet Joseph gives his beard a little trim. I, heaven help me, go digging through my closet for my dreaded foe, the blow dryer. We dig out our nicer clothes, wash our hands, trim our nails. Showing up as the best version of yourself is a sign of respect for the other person's event, whether that be a wedding, dinner, funeral, whatever. As my as I am loathe to get out of my yoga pants, they probably aren't my best self just because I'm comfortable. So, when it comes to body hair, I think the answer is just whatever is the best version of yourself.
On the other hand, I did get myself thrown out of my sister's wedding party for refusing to wear a strapless gown and play the viola that I hadn't played in ten years in front of 400 people while she walked down the aisle. Epic bridezilla fail.
We could have an entire thread on what people do to each other surrounding weddings...but that would probably drive everyone to drink.