I like the concept of sunfall/sunstar becoming a father figure for bluestar because stormtail became a deadbeat dad but sunstar doesn't get with moonflower in a romantic way and neither of them even see each other romantically, they're close friends and sunstar wanted to support bluestar and snowfur because he knew they were struggling especially after losing their mom

sunstar and moonflower hang out in starclan and team up to kick the shit out of stormtail