Does the President have a constitutional right to ask me to pray?

If so, does he have right to ask me to pray to a specific deity? Say the great flying spaghetti monster? If not, should he be expected to invite any other particular deity-worshippers to the White House? If he invites one group, shouldn't the devotees of his noodly greatness also expect an invite? Constitutionally speaking, that is.

Yours, experiencing constitutional indigestion,
N.