This is quite embarassing, but here goes.
When i had my DS1 who is now five, i remember many times changing his nappy, he would have an erection - even from being a tiny baby. I thought it was strange at the time, but in the end, knowing nothing about little boys, i just ignored it.
But after having DS2, now 22 months, i have never seen the same thing. I was thinking the other day, which is normal? I have been told DS1 has a tight foreskin - sorry to be so graphic!! Do you think this could be the problem?