A - Thanks for the question. Is eating meat on Fridays during Lent a sin? Let me tell you that there are two dimensions to this question that we should deal with - the objective and the subjective. I will deal with only the objective part. Because the subjective is for the individual, their confessor and God to deal with, not me. So, what I will deal with is this - is it objectively wrong to eat meat on Fridays during Lent? (For why we abstain from meat - read this.)
Church law says we are to abstain from meat during Fridays of Lent. Previously we were bound to observe this abstinence during every Friday. But, when the new Code of Canon Law was promulgated, it gave the local Episcopal Conferences the option of altering the obligation under the law outside of Lent. The USCCB then decided to allow us to eat meat on Fridays and dispensed all Catholics in the USA from the obligation, but we are still asked to do some penitential act. But, continuing in the same document, the US Bishops say:
Every Catholic Christian understands that the fast and abstinence regulations admit of change, unlike the commandments and precepts of that unchanging divine moral law which the Church must today and always defend as immutable. This said, we emphasize that our people are henceforth free from the obligation traditionally binding under pain of sin in what pertains to Friday abstinence, except as noted above for Lent.Notice the exception. We are still obligated to abstain from meat on Fridays during Lent. But, you might ask, why does the Church have the authority to obligate us to do such things? The simple answer is because Christ gave it to her. "Whatever you bind on earth will be bound in heaven, and whatever you loose on earth will be loosed in heaven" (Matthew 16:19 & 18:18). This binding and loosing is an ancient Rabbinical way of establishing the rule of conduct for the community - with authority from God.
So, it isn't that eating a steak is wrong, it is that when we do so (freely, with full knowledge and full consent) we can sin - because we are putting our own authority above the authority of God given to the leaders of the Church, which is the Body of Christ.
An analogy might help. The state of Texas has the power to raise and lower the speed limit. If they decide to lower the speed limit on the highway that I use daily, I am obligated to follow that law. Not because I may or may not think the speed limit is correctly set, but rather because of the authority of the state. If I choose to ignore the law, knowing the consequences of the law, I am ignoring the authority of the state and can justly be penalized according to the law. In the same way, the Church has the authority to choose the rules of penance for the members of the Church.
Now, on a side note, don't use this post as ammunition against your pastor. If you choose to approach him about this, then please make sure that you do so out of humility and prayer - not to prove him wrong. I would suggest asking him something like this - "Fr., I don't quite understand what you mean by saying that eating meat on Fridays isn't a sin, I thought it was still an obligation to follow this Church law. Can you please explain it to me? Thanks."
I hope this helps.