5 week old refusing bottle halfway through feed

[firstpregnancy]

DS is 5 weeks and 2 days old and has suddenly started to refuse his bottle in the middle of a feed. He has always been a hungry baby, and we've never had a problem with him taking bottles before, so this is quite new.

However, over the last few days, he will get so far into a bottle and then suddenly start chewing the teat, screaming and spitting it out, all the time making out like he is still hungry. He will then cry for the bottle, but do the same thing, occasionally spitting out the milk as well. He seems so distressed. We wondered if it was because he had grown out of the teat, so tried him on the medium (stage 2) Tommee Tippee ones instead, but he still does the same thing. We have also tried winding him, and rocking him to sleep just in case he is actually tired and only thinks he's hungry. He started doing this just during his bedtime feed to start with, but now frequently does it during the day as well. Sometimes he will settle and go to sleep, but not always.

I'm a bit confused and don't know what to do with him, as I don't know if he is really hungry, or if he is full, or if there is something else the matter that is preventing him from drinking the milk.

Has anybody else experienced anything similar? What was it, and how did you deal with it?

Have you tried offering a dummy when he does this?

Thanks! We do wonder whether to start using a dummy with him (for other reasons also).

Although last night he started doing the spitting bottle out thing at the beginning of his feed, so we are now even more confused, as he clearly wanted the bottle. He has fed properly since, so he isn't going hungry. We are just perplexed as to why he does this sometimes and not others. He has already done this once this morning, but he has gone to sleep now, and is quite happy for the time being. It is a mystery!!