Is he just sleeping/napping too much when he is at work with you? If so, then he won't "need" to sleep at night.... LOL
what does he "do" when he is at work with you? Is he holed up in your cubical with you just hanging out?
He probably needs an outlet and more activity IF this is the case.
OR, sometimes at this age they get what is called "night terrors." It is purely developmental AND normal. Perhaps his waking is due to this. Look it up online... most kids go through this.
Certainly, I can understand your need to keep him quiet while at work. But, that takes a lot of patience on his and your part. By the time he gets home, he probably just needs to get his yah-yah's out and does not want to sleep.
Well and he does not seem to be able to "self-soothe" yet.
All kids/babies are different.... my daughter was like that and high-needs and spirited, I just co-slept with her. Finally by the time she was 2 years old, she grew out of it. But now and then she still likes to sleep with us.
And no, she is not breastfed anymore! LOL
But she did self-wean at about 2.5 years old.
Your son is also probably very "oral." And needs to suck on something to calm down and soothe. I'm sure you don't want to do a pacifier at his age, and since he went straight to a sippy cup...but... well... sometimes nothing else will work.
OR... put a sippy cup of water in the crib with him and leave it there... they will "learn" to control it themselves and drink when they want.
If Hubby continues to abhor this situation... (and the neighbors are already complaining), well.... you have to do something. When a Husband's sleep is like this, AND the sleeping with his Wife is altered....it can irritate them. Men have less patience with things like this. My daughter was like that... but bless my Hubby, he had stamina... albeit with some grumbling in between. BUT, you have to consider your sleep arrangements.... in light of Hubby and other needs.
Does your son sleep in a crib, or in your room, or have his own room? If he is right there in the room with you, then sure, he will want YOU and want you NOW! And they see you, and they wake. My girl was like that too. We had a futon in our bedroom on the floor, this is how "we" co-slept. While keeping Me & Hubby's bed for "us."
ALSO, is your son getting enough to eat during the daytime? Some kids, if they don't get enough intake during the day, they will be just plain HUNGRY at night... and wake all night.
Maybe try filling his tummy with something before bed. A banana is always soothing and good for the tummy.
Also, sure he may be teething... try teething remedies... have you tried? Try Hyland's Teething tabs, or Tylenol, or ask your Pediatrician.
ALSO, perhaps get a book on "spirited children" or "high needs children." I"m sure there are lots on amazon.com
Some kids just don't self-soothe well.
AND, in conjunction with "separation anxiety".... it creates a lot of "needs" in them... all day and at night. He is probably with you ALL day, and so he wants to be with YOU all night too. Just a theory, maybe. "Separation Anxiety" will come up all throughout toddler-hood at various times. When they are 2 years old+, it will come up again, in different manifestations.
Good luck,
Susan