I suppose i should know really but i was reading the other thread and it seems like my perceptions are a bit out based on the othe thread.
I was at sils 3rd birth (her dh wasnt at any) i occupied her kids till bil came home to look after them, then at hosp i held her hand and sat next to her, after she had baby i cuddled it while they sorted out placenta (her wish) and passed the mw her pants out a bag
At my first birth, i spent some early labour at sil house, then dh drove me to mlw unit at hosp, i think mw told him to remind me to breathe in g and a (but i picked up on that quick) we were in room alone till i said i was pushing He sat there while i pushed and didnt DO much, not that i wanted him to
At second birth he phoned for ambulance, insisted they come when they thought we just wanted a free ride to hosp, and then when paramedics arrived took some gruesome pictures
For some reason I couldn't speak during labour - i could only whisper therefore my dh was my advocate to get me my epidural. I told him beforehand that if i said i wanted pain relief he was to make damn well sure i got it- and i did.
Are there any prenatal classes the two of you could attend together? Maybe he is clueless about how he could really help -- sometimes there are emergencies, such as needing a c-section, needing forceps, needing some kind of monitoring. It might encourage him to feel more involved and not just see this as some sort of occasion to take gruesome photos, if he could see other partners interested in the welfare of the mothers of their children.
I arranged for an additinal birth partner second time round!
For my friends the most effective have been ones who knew what the birth plan was and "spoke for" their partner when she was otherwise occupied. Ante-natal classes idea good. Maybe ask SIL to be a second birth partner, seems like you have shared some experiences already and you both know what it's all about