Solar Wind develops a huge attachment towards Sunset Shimmer by the time he's 3 months old which would make sense because she is his mother after all and she's really the only person he spends time with aside from his grandma Radiant Sunrise (who spoils the heck outta him). Flash is works a day shift so he's gone most of the day and he usually gets home around 7pm and Solar has gone to bed by then most of the time. Flash does his best to spend time with his son but when Flash wants to hold him, he tends to cling onto Sunset for dear life. Flash doesn't take this to heart but he still does his best to bond with his son. And Sunset, of course, tries to encourage Solar to let his daddy hold him. Eventually, as Solar gets a little bit older and starts showing some independence, he starts to spend more time with Flash, and Flash has a really good knack for making Solar laugh which Sunset really admires.
Solar Wind continues to be really close to Sunset as he gets older so you could say that he's VERY much a momma's boy. lol
Flash's anatomy looks way off here but other than this, I really like how this drawing turned out.
My Little Pony: Equestria Girls is (C) Hasbro Studios
Solar Wind, older designs for Flash Sentry and Sunset Shimmer are (C) me