GF hit me over an off mark insensitive joke

[CHickenNugget]

My girlfriend and I have a pretty good relationship. We're happy together, despite the occasional ups and downs that naturally come with being in a relationship and we have been together for 1.5 years.

However, something happened about six months ago that I've been thinking a little bit about. I struggle a bit with OCD and generalized anxiety, so I wanted to get some outside perspective on whether I'm overthinking this or whether it's legitimate to question if we should still be together.

I was sitting playing FIFA and asked my girlfriend to open a pack. For those who don't know, a pack contains a random player.

I ended up packing a female footballer and jokingly said, "Oh no, not this fat chick. She's not even that good."

My girlfriend then slapped me across the face.

I immediately said, "What the f*** are you doing?" to which she replied that I should speak more respectfully about women.

I told her that she should never hit me again, and she instantly apologized.

Even though we're quite adventurous in the bedroom and enjoy things on the rougher side, slapping has never been part of our sex life. And for me personally, being slapped is a huge no-go.

There hasn't been any other form of "violence" since that incident. And she's been very sweet and carrying, I have never seen that side of her since that 1 incident.

Still, I'm not entirely sure whether I feel comfortable continuing the relationship or whether I'm just looking for an easy way out.

I'm going travelling again in January, and I know she's going to miss me a lot, but damn, I'm really struggling to figure out whether this relationship is worth continuing after what happened.

I also realize that breaking up with someone 6–10 months after an incident like this might seem a bit unfair, but I just find it incredibly messed up that she would slap me over an inappropriate joke.

I'm 22, and she's 21.

TL:DR Girlfriend slapped me jokingly? Over an immature joke.