Neither.
With as much empathy and sensitivity as possible, I would ask him, if he sees a problem with the relationship, why he wants to go to a psychologist--and not a relationship counselor together? Because if he perceives a problem in our relationship, it's also my problem, and I want to be a part of the solution.
By responding in this way, I demonstrate the following:
1) solidarity and support of my partner
2) a desire to be a part of the solution and not the root of the problem
3) an openness to communication without pressuring him to directly disclose the problem in the moment
I mean, what he's said is pretty vague and cryptic, but I actually find it encouraging for a few reasons:
1) He's taking the initiative to go to counseling on his own. That indicates that he probably thinks the issue is with his reaction and how he perceives the problem. I don't think that he sees you as contributing to or creating the problem. Otherwise, I think he would be trying to get YOU to go with him. This shows that he is pretty self-aware, which is a good thing.
2) He told you about it. This shows that he wants to be transparent and open with you; he's not trying to keep secrets or blindside you. He's not telling you now what the problem is, but he will eventually tell you, whatever this is. He just may not be ready.
3) Whatever this problem is, he wants to fix it, which means he is invested in the relationship and wants to work on making it better. He isn't planning on walking away any time soon.
I don't know if this applies to all men, but my partner needs time to sort things and think about things before we can hash them out and resolve them, whereas I (the woman) wants to resolve it right away, and get everything out there. So I usually unload everything in the moment... and then he needs some time (how much depends on the issue), and then we come back together and talk about it again. And then sometimes he needs some more time to think. Men are not always well connected, identify easily, or even understand their emotions, and they need time to sort that out and figure out what exactly they are feeling... and then they have to figure out if it's something that they should act on, or if the feeling should be disregarded and acted against. So your partner is likely seeking out a counselor to help him figure out how he really feels about this issue before bringing it to you, which is actually quite thoughtful.
Best of luck, dear... I hope it turns out well.