Maybe make Pinkies smile a little smaller, so it looks like her lips are more connected to Flutters rather than being nuzzled. Though its a hard feet, one of my Twishys pictures for their first kiss looks like they are getting some tongue ^__^; it wasn't intentional.
Like others are saying, a little more detail in the lips could help. Perhaps make them look slightly more puckered out. Kind of like what you did with fluttershy's lower lip, but ever-so-slightly more pronounced. Not sure how well it'll work since I can't hand draw for shiz and I'm not exactly an art expert, but hopefully the idea will at least help you out.
It's especially hard for characters whose faces aren't really well shaped for human-like kissing. What you have here doesn't look too bad, but I feel like there should be more detail in the lips. Otherwise it just looks like they are nomming each other.
There's nothing wrong with girl/girl ships you know I don't believe he was objectifying anybody at all And this isn't smut??? Really it's not I don't think It's just kissing and it's not even like they're making out literally just kissing I don't think that counts as smut