Slept with my co-worker... but surely this isn't normal?

Yes, I know - don't s**t where you eat. I started working in a bowling alley, which had only been open for 2 weeks when this happened.
I found this boy attractive from day one, and we always had some weird tension between us. A week after, my work team decided to go out after work, me and this boy both got drunk, went away from everyone we worked with, started kissing, went back to his and slept together - this probably wouldn't of happened if we were both sober. We have very similar personalities in that we don't take things too seriously, so the next day we laughed it off and it wasn't awkward between us.
When we went in to work next, it WAS awkward only because everyone at the night out had clocked on we disappeared together. They asked us questions and we both just came out bluntly that we had both slept together and I said it was a drunken mistake and wouldn't happen again. This was almost 2 weeks ago. On that shift, people made comments and I felt like I couldn't go up and talk to this boy like normal because people would be smirking. I expected it though, obviously sleeping with a co-worker.

What I haven't expected is, since coming home from Christmas, it has been the subject in the group chat every day. It is the same group of 4 people in work. They have basically posted what happened in the chat so EVERYONE knows now, they have called me and this boy 'strays', they have said that I am a beg with little self control. One of them joked that I'm '3 weeks pregnant' and another girl implied 'it will be 10 weeks before she notices' . People are responding with laughing gifs and telling me to 'clap back'. Me and this boy both have laughed it off in the group chat, but I am definitely getting more criticism than him (guess its double standards)
At the end of the day, I know i brought it on myself and I expected to get wound up the day after but I don't see why a small drunken fling has caused me 3 days of non stop abuse every time I speak in the works chat. Like I said, I don't take things seriously and I mainly find this funny but at the end of the day I don't want this to carry on and to feel uncomfortable in the workplace. I'm being made out to feel dirty and like I've done something wrong - when it was a mistake and its human nature to do when your drunk, single, young and next to someone your very attracted to. Me and the boy both never cared about it, so its just been blown out of proportion by everyone else. I am a very confident person and this is getting me down, so imagine how someone a bit more insecure would feel in my situation. What do I do? Do I carry on laughing it off, or do I say something, thing is I don't want to cause more drama - but I guess I could always phrase things nicely. Or should I have expected this giant mantra of hatred towards me? When I say it is non stop in the chat... I mean it is literally NON STOP for 3 days straight. Will it blow over? And even if it does.. .I don't want people to think they can say things like that to me - do I just bite back when someone puts another comment in the group chat, tell my manager or wait until I see them on shift and bring it up? Basically - I know I made a mistake but how the hell do I handle this... because I know this level of abuse is not normal!

by 'co-worker' do you just mean colleague?