Should my boyfriend own a suit?

Background: My boyfriend (29) grew up poor but now both he and I (25) are employed with decent jobs. He’s really outdoors-y and doesn’t own a suit (he works outdoors and just never needed one for interviews or been to a fancy wedding). We were invited to a wedding in that he would need to wear a suit for. It’s for a very distant relative of mine. He said he didn’t want to go, and I didn’t have a problem with that. I still maintain my independence & it would be a good time to connect with some long-lost relatives. I know if I pushed it, he would buy a suit and go with me, but I don’t want to make him uncomfortable. My dad says my bf should own a suit, or at least dress pants and a sport jacket.. I feel like that’s unnecessary but am wondering what you guys think. 🤔