I guess pay attention to what our gurus are saying -- but sometimes people turn to "new" people to express themselves or ask questions. Sometimes they just need another outlet - maybe one that doesn't carry w/ it a history or any implied pressure or maybe just someone who doesn't know all the details. If its only been a week, the other person also has obviously not seen when being around a person in contest prep is like. I STILL can't mention diet around my mom without her getting upset and leaving the discussion. And its been a year and a half since my first show.
There are insane amounts of pressure and physical stress from contest prep. So I think its hard to judge someone while they are going thru this - even if they've done it a hundred times before. Just give them space and time and let them know that you are there for when they need someone who is familiar with the routine. I"m not saying tolerate any bullshit in your relationship, but give some space and don't add to the current pressure. And also make sure you don't put more pressure on yourself about the state of the relationship. If your relationship is strong, it will survive regardless of what he says. That alone should give you enough confidence to give the space and not aggravate the situation for you or him. If you are unsure, then decide how long YOU are willing to be tolerant before you decide it is truly time to cut the ties.
My opinion anyway. I lost a lot of friends and one growing relationship during my first competition - expectations and assumptions about who should "be there" to support you and put up with you are rampant during competition prep. That's just the way it is. SHouldn't be that way, but it just seems to be.
Also wanted to add that when you give people an "ultimatum" like "if you had to choose now...." they sometimes freak out and get defensive. Then the whole argument starts over. Its a frustrating question to not get a straight answer to, but its hard to provide a straight answer when you feel like like you are being given an ultimatum. Not saying its wrong, just saying its a time when the reaction shouldn't necessarily determine how you will respond to the whole situation (e.g. he doesn't sound convincing / I think he's lying, etc.)