If you have already been to see your primary care doctor
about this a few times without figuring out what is going on, then it might be time to make an appointment with a dermatologist
, who should be able to help you get to the bottom of this. One thing that would be very helpful, in preparation for this visit, is to take photos of the bumps with your phone or camera, since it seems like they tend to come and go and might not be present when you actually go to your dermatology appointment.
It sounds like you've already ruled out a lot of things, such as a reaction to a new soap or other personal care product. A mild form of eczema
would still be on my list of possibilities, since this often will "flare" after a warm shower.
Also, it is important to consider bites, particularly bed bug bites, which are classically intermittent and very itchy. They also are something that can be easily overlooked in the workup for this type of skin condition. The fact that your boyfriend also has them makes this perhaps a more likely possibility.
Start by making an appointment with a dermatologist!