Preventing engorgement?

My baby is 6 weeks old, and so far I've left him twice. Once was my birthday when he was 4 weeks, and I left him with my parents during the evening while I went out with hubby. He had 2 feeds while I was out (should've fed him just before I left him, but I think my mum was pretty keen on feeding him, so I let her do that one with the bottle!) I also made sure we had enough expressed milk to last through the night, as I knew I'd be able to have a drink while I was out that way. Also, hubby said he'd do all the night feeds so I could have continuous sleep - what a birthday pressie! I also left him last Tuesday for an hour and a half with my MIL and she gave him a feed while I was out, but once I got home I fed him as normal.

Both times I've had really swollen, painful boobs as a result of not feeding him which I think is engorgement. Tuesday wasn't as bad as the morning after my birthday, when they were so so bad I leaked all over the bed sheet (I hadly ever leak ever) and they were like rocks, really painful. I felt sore for a couple of days, although the hardness went after the first couple of feeds on each side. Tuesday night, when Jak woke me for his midnight feed, I was really painful on my left side, but it went more quickly.

Is there any way to prevent it? Hubby has suggested expressing when I get back after going out, but if I've missed a couple of feeds, won't it still hurt loads? Also, if I've had a drink while I've been out, I'll just have to chuck it away won't I? We're really lucky to have my parents, who are extra keen on looking after Jak for us, so hubby wants us to have one night out a month to ourselves, and he wants to then do all the night feeds so it's a double treat for me. However, if it's going to result in engorgement every time, I don't think it's a great idea!