Can you change your Facebook relationship status to being in a relationship with someone w/o their consent?

[Shorty]

I'm fairly certain I know the answer to this, but I want to ask others before I jump to conclusions. I've had a complicated on/off relationship with a guy for several years now. We've dated other people for basically the entire time we've known each other and talk to each other in between. It's been like this since I've known him. I hadn't spoken to him since April of this year, but we had a pretty serious conversation last week, and I asked him if he wanted to be my date to my brother's wedding. The NEXT morning, I woke up and was checking Facebook when I saw that at 2:00 in the morning his relationship status changed to "in a relationship" with another girl. I confronted him about it since the night before he had told me he definitely was NOT dating anyone. He was apologetic, and said he had told her NOT to change the status a long time ago because he didn't want a lot of questions and drama from "a million people." He said that she sent him a text in the middle of the night saying she had changed her relationship status and TAGGED HIM IN IT and hoped he wasn't mad. He claims Facebook would not let him change the status or hide it from his timeline, and when I made him promise he wasn't lying to me about her, he got angry and said no. That was the end of the subject; I told him I believed him. Then on Saturday I saw he was tagged in a her status and they were at a football game together "having a blast," and as of today, the relationship status is still on his timeline.

My question is if he is lying to me and he would have had to confirm the relationship status change for it to appear or is there a way that I don't know about for her to have done it and have it show up in the newsfeed without his confirmation? My last boyfriend did not have a Facebook account so I'm not sure if there's a way to do it that I don't know about which means he was telling me the truth.

Thanks for your help!
Thank you, Mrs. Jones. I specifically need to know if he was lying about her being able to "tag" him in the relationship status change and have it appear that they are in a relationship together. I always thought you had to actually confirm the change before it would appear meaning he lied to me.

[Mrs Jones]

You can hide your relationship status. All you gotta go to is edit profile.

[abraXus]

not without consent, no

[Pamela]

When you say you're in a relationship with someone on Facebook, the only relationship status that gets changed is yours. It will say that you're in a relationship, but it won't say who you're with until that person confirms it. So yes, he's lying. Sorry. :/