1. You know him better than anyone. Why wouldn't you want to spend time with the person who understands you inside and out?
2. He can't snuggle with his bros. This is a pretty big deal, and it makes things like camping or an overnight trip way different experiences when he does them with you as opposed to a group of his friends.
3. You make shopping in a hellhole supermarket for an hour bearable. Sure, going on vacation or taking a trip to the beach is fun, but that stuff can be fun with pretty much anyone. Going grocery shopping or taking a trip to the recycling center? That stuff is only fun because he's there goofing off with you.
4. It'll be OK if he wants to end your walk early because he's hangry. He can show his weaknesses in front of you. Which basically means when you're out on a hike and he wants to leave because he hasn't eaten in hours, he can do that.
5. You can turn dumb errands into a lunch date. You can start off running errands and then decide to check out some small bistro that you pass and grab lunch. Suddenly, you've turned a boring afternoon into an impromptu date.
6. You can just lie outside together doing nothing and still be perfectly happy. Even just hanging out in a hammock reading books is nice with you. He can't call up one of his friends and be like, "Dude, come over and grab some beer. I just put the hammock up and it's so nice out. We can read books in it together." I mean, he can do that. But he won't.
7. You always introduce him to some fun new thing. He never feels like he has to call you just because you're the person he goes to football games with. He calls you because he knows he's going to learn something new every time you hang out.
8. He can take selfies and brag about what he's doing without looking like a weirdo. Did you just go to Boracay together? Or try a new restaurant? Well, he can take a pic with you and upload it and get everyone jealous. It just feels sad if he's doing that by himself.
9. He wants to make memories with you. He's trying to make some stories you'll tell your kids one day, so he's getting pretty serious about this.
10. You get him out of the house. When guys hang out, they fall into old patterns. And that pattern usually takes place in their living room. On the couch. In front of the TV. There's nothing wrong with that, but you're not going to want to do the same thing every time you hang out, and that's a good thing.
11. Your face always cheers him up when he's glum. His friends are supportive, but guys also like to give each other crap. If he had a bad day at work, he knows hanging out with you will make him feel good.