growth spurts will do this. so will developmental stages like crawling, standing up, walking. also teething. this is NORMAL BEHAVIOR for an infant. feel blessed that your baby has slept so well. trust me, as a mom, you wont EVER get a good nights sleep again; even when they graduate and leave home you will be up at night worrying about them. just be patient with him, listen to his needs, and stop setting him up for failure by saying things like "i know he is capable of sleeping through the night" because kids are NOT always capable of sleeping through the night. think about it; how often do you get up at night to get a drink, go to the bathroom, turn over, hit a snoring partner, whatever. babies are not soldiers. dont expect them to act like one.
white noise, dim lights, whispered voice, even things like not looking directly into his eyes are all things that can help not rouse your baby more than he already is. remember thuogh, the more he cries, the more awake hes going to be. if you can catch him at his needs the first wimper, you've won half the battle already.
its not "baby him" its tend to his needs. your husband is following his instincts, and you should follow yours. dont let the whole world tell you something is wrong. if you let him cry it out are you really going to be able to sleep? im sorry, but theres something insensitive about a parent who can sleep while their baby is in the other room crying. just doesnt sound like a plan to me. i have a four year old who NEVER cried it out. ever. he goes to bed like a dream, he sleeps like a dream, and he gets up in the morning happy and ready for the day. sure, some babies are releasers and need to fuss a little to relax but most babies are increasers and their panic will only increase by being left to cry. think about it this way: if you had a need, you were hurt or something, and no one cared, how would you feel?? you would feel pretty rejected. think about it; your baby doesnt understand the world yet. just relax. theres no such thing as a baby who is "too attached" to his parents. i mean really, isnt that what we want? dont we want kids who are attached to us? dont we want kids who feel like they need us? dont we want teens who trust us so much that we are the first person they come to with a problem? think about it over the long term. no you wont sleep full nights for the rest of your life. but really, no one does. we all survive. put sleep first, stop worrying about chores late at night. record your tv shows, or just forget about watching them, and netflix or hulu them later. go to bed earlier. do what you need. dont overstress yourself, and dont overanalyze this. your baby is just going through a phase, this will pass and be replaced with something else soon enough. lol.