interested without hurting his feelings?

after work yesterday, one of my coworkers and best friends asked me if i wanted to hang out and grab some drinks. that seemed innocent and fine, but then his vibe and the type of questions he was asking ("do you like kids?", "do you still talk to your ex?" "you really remind me of my ex", "haha wouldn't we make a great couple?") felt like more than the usual just-two-ppl-getting-to-know-each-other-better-type convo

to be honest, i don't want a relationship with him because he's just not my type. he's cute but he's like 5'7 and i think that we get along better as friends instead. he does really nice things for me like when i show up late at the lab he'd have everything set up for me and he buys me food during his lunch hour so i dont have to waste my lunch hour waiting in line at the cafeteria. and in return i hang out with him by letting him take me out every other sunday.

i really dont want to hurt his feelings because i dont want to lose that special friendship that we share. so i'm at an impasse. i'd be a terrible person if i just led him on but at the same time it's cool to have a guy friend who i feel like i'm in a fairly equal and balanced friendship with and i don't want to lose that.