To confess this and ask for help

I’m good thanks.

You need to think of him as part of the holiday. Over now. The environment and opportunity out there made this far better than it would be in every day life when he's just another dime a dozen guy who you'd not be able to trust as far as you could throw.
Youll do yourself no favours hanging on with your finger tips to some crumbs now. He'll get fed up as he settles back to his every day and will contact you less and less, so you'll need to accept that at some point. Why prolong the misery?
You probably also need to work a bit on the value you place on yourself. What on earth possessed you to allow yourself to be some chancers holiday shag? Mate. C'mon.

“Catch feelings” is one of those naff social media generation phrases decided to absolve the user of responsibility. “It wasn’t my fault; I didn’t mean to do it; I couldn’t help it - I caught feelings!”

You catch a cold, not feelings. The only feelings he had were in his crotch. Move on and make a promise to yourself to not fall for such flannel again.

Go and have another coffee.

Sorry this is harsh, but have some self respect he's in a relationship and keeping you on the side you will never be a priority to him and he probably won't break up with his girlfriend

She didn’t say it wasn’t.

There is no point saying you made a poor decision and are ashamed of it, at the same time as planning to continue the 'fling' by calling him at work. If you genuinely feel remorseful, have nothing more to do with him.

Yeah but the lions share is with him

You need to cut contact and work on your self esteem. There's a part of you that wants to believe he never intended to cheat but there's something so special about you that he couldn't help himself, he's lying. He went to cheat, he never intended to leave his partner and would hate for her to find out which is why he can only contact you when she isn't around. He is deleting your messages and pretending you don't exist.

He has been very clear that it was just a fling but unfortunately you developed feelings for him. Best block him now and start the recovery process.

He is a cheater. He will cheat again. Make sure he doesn’t get the chance to cheat on you.

She can hate both of them.

Reflect on your very poor choices, how you value the standards of the men you interact with and try to be a better person going forward.

There's another thread on this subject currently. Don't blame her so much, blame your idiot spouse who can't keep it in his pants.

Oxytocin is a strong drug.

It will fade though - as long as you have nothing to do with the man.

Try to get out and meet other people, get busy, do new things..... Take your mind off this.
Try to meet a single guy.

This one is not single and his behaviour strongly suggests he is not going to make himself single.

The 'please be gentle' requests on such posts are indicative of a disingenuousness and selfishness.
Trying to defend the indefensible by faux regret is not a good look. How would you feel if your oh came back from a holiday and said 'by the way, I fucked another girl while on holiday; told her about you, but she was willing to shag me for the rest of the week, so I went for it. Is that ok?"

So the poor thing never expected to have feelings for someone else and cheat: Why isn't he breaking up with his gf to be with you now then? Why is telling you he can only call you from work? Because he wants to have his cake and eat it. You're probably not the only one he's calling from work. Just look at this as learning experience OP: never get involved with someone who is already in a relationship because 1. You will get hurt. 2. You're worth better than a cheat.

He doesn't have feelings for you as he's incapable of any. He doesn't understand loyalty, empathy, respect etc..

You were just a quick shag I'm afraid. No doubt the latest in a long line so please get yourself checked and work on your self esteem that you fall for such rubbish.

Op if you were meant to be he'd be leaving his gf for you. Hes not. You need to go cold turkey here and tell him to get in touch if he's single in the future and if you are too you can go for a drink.

Forgive yourself & move on.

He will have been waving you off at the airport and picking up a new one on the way to the car park. I was a holiday rep many years ago. For barmen, shop and cafe workers, shagging the holiday makers is on of the perks of the job.

It rarely works out & it rarely rarely works out when the person is a cheat who wants to stay with his partner & remain a cheat keeping you on the side…

Did you & your sister break up someone else’s relationship to be with your holiday fling? Did you spend your life worrying if he’ll do to you what you did to his ex? Or did you get with someone who was single which worked out for you? Would it have worked if he was wanting to play happy families with his girlfriend & only contact you on the snide?

Even meeting someone on holiday who is single is very different to real life. Holiday flings are just that, a fling. It’s very very very rare for it to lead to anything meaningful in real life, even more so that you know he’s a cheat. The way you get a man is the way you’ll lose him. Just keep in mind that if he ever went on holiday again without you you’d be thinking who’s he going to be with? Keep the memories but move on. You don’t want to break up a relationship for something that isn’t real. You know you shouldn’t have done it & you know you shouldn’t be breaking up a relationship. Move on & let them be. Someone who cheats as soon as he has the chance isn’t someone you can be with long term especially I’m assuming long distance?

Tbh OP, he is showing you where his loyalties lie, and it isn’t with you. He clearly doesn’t look on it as worthy of splitting up with his gf for, or he would have split with her. He is giving you a few crumbs - letting you speak with him on his terms, probably because he likes the idea of having someone on the side, but I’m guessing it will just fizzle out now the holiday is finished. Delete and block his number, keep your dignity, and just chalk up to a holiday romance.