As long as you know her well enough to know whether to, when to -- and when NOT to -- come someplace on her body, who's to say you're weird? You two are the only people that matter. If you're on the same page and you know each other's likes and kinks, you'll probably know whether coming some particular place is OK. If you don't know, talk to her about it (preferably sometime when you have more than two seconds to blastoff
).
What I wouldn't do is pull a sneak attack, like in porn movies when a guy pulls out and suddenly blasts across a woman's face without warning. You may never get close enough to try again.