2 months+ LO

1. I have a LO who would become agitated and cry murder when the bottle is taken away from him to burp. This would cause the milk to be puked out and hence we always wld continue to feed him without burping him. We would try to burp him after the feed but most of the time no burp, and he would puke a lot of milk out either almost immd or few hours later. Any idea why is this the case? 2. Is 90ml for 2months+ lo sufficient? 3. Is drinking 90ml in about 8 mins considered fast? And if drinking 90ml in 15-20mins considered slow? We are not sure if the teat has problem(currently using NUK latex 0-6mths S size teat) #firstbaby #1stimemom #advicepls