My partner has had a history of having an issue with drinking. Sometimes too much, sometimes too often, once he starts he can't stop etc. Our relationship always gets tense at social occasions or holidays when there will be alcohol. I enjoy a drink myself but I'm able to manage my drinking. He always drinks the fastest and gets the drunkest at weddings and parties. We have a 3yo son and our last family holiday (us 3 and my parents who he has a great relationship with) was great up until the final day when he disappeared on his own and came back hammered. We have had a few separations, generally me moving to my mums for a month or so but there was a stage when he moved out and got a flat for about 6 months. Anyhow...trying to get to the point...we had been on good terms before holidays and things had been great, I had been relaxed around his drinking and we had a great time until the last day. He knew that the holiday was a make or break thing and he was really embarrassed and ashamed that he had let things slip back so we agreed it would be forgotten about and start afresh. We came home from holidays and I am now 16 weeks pregnant with our second. This past 3 weeks there has been a few minor occasions where I see things slipping back into a pattern that I find uncomfortable (going for a drink after work and not coming home til 1am, drinking at home etc). I was beginning to think I was annoyed about this behaviour because of hormones. This weekend he offered to take our son to his parents for the weekend (they live 2hrs away) to give me a break. So he had drank a few cans (8) in the house on Friday which I didn't really like but didn't say anything, yesterday evening he met a mate for a few pints and told his mum that he would be back at 7 for our son to go to bed and because he had the car keys in his pocket and our sons dummies and stuff was locked in the car. At 10.30 she couldn't get an answer from him so rang me to try and get in touch with him, which was met with abuse. He apologised this morning and I just let it go. I have been a bit off with him today because I was worried about how things seem to be going back to an old pattern. However, I have just discovered that he has been texting me pretending to be in his parents house and he's actually sitting in his brothers friends house drinking. I'm highly strung and really stressed at the moment (partly due to being disappointed, partly due to pregnancy hormones).
Am I being unreasonable for this to be the last straw?