If you're having lessons on the flute, I'd ask your teacher first ... I know that flute embouchure is as critical as trumpet embouchure. I do know someone that plays tuba and flute to a high standard, but I suspect many flute teachers would have palpitations at the thought. Maybe that's just because brass players are so so vulgar.
But a word of caution - the trumpet isn't really an instrument I'd recommend as a 'part-time' instrument - it tends to be one that people play pretty seriously, or not at all, as it does require a decently maintained embouchure to get a good sound out of it over a useful range. Certain other instruments tend to be more forgiving about days off.
QUOTE(kenm @ May 6 2008, 03:41 PM)

I recall being told by Alan Lumsden, professional trombone, ophicleide, flute and recorder player, in 1970 that most brass teachers had changed to teaching "high embouchure" (2/3 upper, 1/3 lower) for all instruments. Being a horn player, I don't have direct knowledge of trumpet, but my son was taught high embouchure for trombone c. 1980..
There are different schools of thought on this - horn
tends to be more upper lip than lower, and trumpet vice versa, but some trumpet methods do go for the more-upper-lip set-up. I'd agree that trombone tends to be more upper lip. At the end of the day, I think it's whatever works best on the individual's face, but you might want to look at the technique forums on Trumpetherald to read more:
http://www.trumpetherald.com/forum/index.php?c=5