Obv the 30 mins in the bathroom is unacceptable. But where do you draw the line? As I said on other thread, when dh is not around to look after ds, then I do feel justified in sometimes "ignoring" ds in order to give the dd's some attention. ds is a terrible sleeper and will often go to sleep later than the dd's, so waiting for his bedtime not an option.
My kids are quite close in age and fortunately like much of the same things. I worry that I let the eldest (she's 3 1/2) do more at the park on her own than I should as I am constantly hovering near DS who's almost 2 so he doesn't fall off etc. I find the balancing act (no pun intended) really hard, but maybe that's for another thread. Perhaps this is a time when you could sit DS in front of a DVD for 20 mins while you attend to the other two?
I have two boys aged 5 and 7 and a dd who is just coming up for 8 months.
When they were younger I found it hard to please both of them and give individual attention when I was home on my own, so opted to do things like reading stories as a family, rather than individually, eg both would get to choose a book and we would read both. I then did things with them individually when dh was around and could occupy the other one.
Alternatively I would set them both off doing different things (craft/drawing/puzzle etc) on opposite sides of the table and then help them as they needed it. I did have to teach them that if I was helping the other one they would have to wait a while for my attention though, but I felt this was important for them to learn as once ds1 started school and had homework I would have to focus on him exclusively for a while each evening.
Now they are older we still do the family time thing for reading etc and they even read their school books while we are all sat together on the sofa so they get to read a story and listen to one. They do their homework together at the table, with dd in her highchair and I move between them as and when they need my help. I also like to arrange a day or afternoon a month for each child to come out with me to a cafe or something on their own so that we get a bit of exclusive time as well.
I think doing so many things together has actually helped my boys, their teachers say they have never seen two brothers so close and spend so much time playing together. Don't get me wrong, we still have jealous moments, ds1 in particular gets jealous of ds2, but I think that is to be expected in a family of three children. I guess its an extension of learning to share really.
tadjennyp, I think the giving less attention in the park thing is a natural progression for parents of more than one child. Its not necessarily a bad thing though, as long as you are keeping one eye on them to make sure they don't do anything really dangerous. Its part of growing up to be allowed to do more things than your younger siblings and helps them to build confidence in their own abilities.