How to keep temporary distance with a guy you like?

This guy is technically my ex - I say technically because we did date but only for a few months last summer. Anyway we still work together and are friendly again now...

1. I asked him to the cinema the other day because we're just friends and he asked me a week or two before and we had fun. He said he could make Monday or Tuesday. Tells me he can't make Monday cause he's going out with his mates (who are also my friends - these friends also invited me so I ended up going too).
So, cause he couldn't make Monday he said he could do Tuesday so I changed my shift with my manager and everything so I could start and therefore finish earlier to go. Whilst there one of our friends invited me out with them again - said my ex was going out with them too....even though he said he'd be coming out with me? So I text him saying I've heard you're going out with the guys so we'll go another day....

2. He practically asked me to pick him up from his mate's house the other day around 12/1am which was fine cause he knows I stay up late. Ended up waiting up until 5am and he still wasn't ready so I had to go to bed because I had to get up for work like 4 hours later.

So yeah, I feel like I'm kinda bending over backwards for him and he doesn't notice/care although he has started making an effort as opposed to the months we barely talked unless we had to at work.
How do I take a step back without full on ignoring him so he knows it's not good enough to do what he's been doing?