Last night, I attended the annual convocation for deacons in my diocese. During dinner, one of the deacons — a classmate of mine, in fact — told me about a particular problem he was having with his pastor.
“If I’m not preaching,” he said, “he doesn’t want me to read the gospel. He wants the person who is doing the homily to do the gospel. What can I do about that?”
Well, as a priest in my parish likes to put it: just do the Roman Rite. Life is so much simpler if you just do what you’re supposed to do, instead of what you’d prefer to do, which is almost never an improvement.
I’ve run into this problem once or twice before; a few years ago, the priest who was preaching the homily for a deacon at a funeral mass insisted on also reading the gospel. The deacon supervising the liturgy informed him that a deacon really should do it, and the priest relented.
To clear up any confusion, it might be worth revisiting the General Instruction of the Roman Missal (GIRM):
By tradition, the function of proclaiming the readings is ministerial, not presidential. The readings, therefore, should be proclaimed by a lector, and the Gospel by a deacon or, in his absence, a priest other than the celebrant. If, however, a deacon or another priest is not present, the priest celebrant himself should read the Gospel.
I don’t think it gets much clearer than that: the celebrant is not supposed to proclaim the gospel, and only does it if no one else is available. In fact, the deacon should do it by default.