AIO my boyfriend ruined our 5 year anniversary by masturbating

My (25F) boyfriend (34M) have been together for five years. Our relationship has been mostly positive, but in the last two years I've noticed consistent tension and distance between us. We are fighting more often, spending less time together and don't have sex at all anymore.

I was looking forward to our fifth anniversary in hopes of getting us back on track, both physically and emotionally. Admittedly, I've put on a little "comfort weight" over the course of our relationship. My boyfriend claims he doesn't mind, but I suspect that his true feelings about it are to blame for our lack of intimacy.

Anyway, the night of our anniversary arrives. We go out to dinner at the restaurant where went on our first date and things were going surprisingly well, though I could tell he was acting slightly nervous. I feel a wave of excitement and think, wishfully: "He's going to propose tonight." Part of me thought this was too good to be true, but we had discussed marriage in the past and I stupidly hoped that a proposal at this time might salvage our relationship and allow us to recommit to each other.

We return to our apartment. It's like we just started dating again. Things feel great. We go to bedroom and then he drops the bomb: "I want to try masturbating next to you tonight." Well, he didn't say it exactly like that, but that was the gist. I was shocked and confused. He explained that he wanted to reestablish our intimate relationship and that this was the way he felt comfortable doing it. However, from my point of view he wasn't even interested in trying to have REAL intimacy, ya know? The idea was at least something, and it seemed to be heading in the direction of reconnecting intimately, so I decided to give it a try.

It was awful. Awkward. Impersonal. Estranged. My boyfriend of five years masturbating in our bed inches from me on our anniversary.

AIO? I want to be open-minded to what he's comfortable with sexually at this rocky stage in our relationship, but I'm not sure if this is for me.